Thanks to Jan and Flex have my DIY GPS up and running. Next up is the heads up display to link with it...this should be fun.

Nice one Roo, will be interested in what you come up with for head up display. I fiddled around a bit with this. First I printed a case that had the display pointing forwards on my helmet clipping into the gopro fitting and used a full mirror visor reflecting into a partial mirror. The curved mirrors distorted the image too much but the concept worked ok with flat mirrors in certain light conditions. Then Jan inverted the image on his unit which meant only one mirror required. I found the only way to get a reliable image in all light conditions was to have the epaper display facing straight up into the partial mirror (pretty much identical to putting the display on your dash in your car reflecting up into the windscreen.) I made a test jig and worked ok riding around. However I gave up on this as it requires mounting the display somewhere near your chin and would either require a motocross style helmet to mount or increase danger to face in the event of crash. A few pics attached of the ideas I tried. The other concept (as helmet mounted units offer the best GPS position) was a swing down unit that normally parks on top of helmet but can swing down for easy viewing as required. The boom mounted units have worked so well I sort of gave up on chasing the head up display as I think it requires an active display to be viable (in which case you could mount the display forwards as per first pic and it would work in all light conditions). If you really need the accuracy of head mounted unit then just strap an extra or two units on the helmet (as per what Jan does which you can see in the videos he posted). A few pics of the different concepts I tried and what the head up image looks like.

I remember this from my childhood !!!!

Yep, Seanhogan, that's the goal...these little OLED displays would deliver exactly that, though probably would integrate into face visor...

Hi, is the source code for the firmware available somewhere? I am thinking about building this for my daughter's sailing boat for training purposes.

The compiled bin code is free available, just send me a pm. Here a link to the build-instruction : docs.google.com/document/d/1XJD6BV1Xay4nXo0cDuo_IOtxC_f1LyG7DE7X6KGlAB0/edit?usp=sharing

Folks I really appreciate all the work put into this. Last week I realized the limits of 1hz gps and couldn't find a 10hz or higher unit besides GoPro and garmin action cams (I assume the reason is battery power in wrist mount units) after hours of searching until I found this forum.

I got all the parts ordered and can't wait to get it going.

My lack of electronic ability will become clear now.

So the lilygo screen has a chip in it that we flash with software, the "computer" running the software. What other screens can be used? How can I figure out which ones will work that can be flashed with the existing code?

Ideally I'd like it smaller, maybe a little bigger than the gps board and to update the screen at 4hz.
Would this screen work? (Lilygo 1.5"). Or an LCD of similar size?

m.aliexpress.com/item/1005003105619426.html?spm=a2g0n.detail.0.0.245e9c8caLK7qE&gps-id=platformRecommendH5&scm=1007.18499.251974.0&scm_id=1007.18499.251974.0&scm-url=1007.18499.251974.0&pvid=5c0ab26f-76f4-4db4-89cf-c197ef1404b6&_t=gps-id:platformRecommendH5,scm-url:1007.18499.251974.0,pvid:5c0ab26f-76f4-4db4-89cf-c197ef1404b6,tpp_buckets:668%232846%238114%231999&&pdp_ext_f=null&compareFields=formatted_price:US%20$17.74;itemId:1005003105619426;freight_formatted_price:null;source:recommend-sku;is_freeshipping:null;trade_order:52

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JohnnyTsunami said..


Ideally I'd like it smaller, maybe a little bigger than the gps board and to update the screen at 4hz.
Would this screen work? (Lilygo 1.5"). Or an LCD of similar size?

Unfortunately, the update rate of the e-paper is a limiting factor for the "reading" of the speed. With the 2.13" version, the "partial" update takes around 1s. The logging to sd is independent of the refresh of the screen, so this can be set at 1,2, 5 or 10Hz. The "compiled" software of the logger is free available, just send me a pm. But if you plan to use other hardware (1.5" e-paper or LCD), it will not work. This will need a considerable effort to changes in the source code.
I have considered to order such a screen and do some testing, but there is no sd-card slot, and you have to add a gps, and it is not waterproof. In the updated manual, you will find a description how to flash the T5 board for the first time : docs.google.com/document/d/1XJD6BV1Xay4nXo0cDuo_IOtxC_f1LyG7DE7X6KGlAB0/edit?usp=sharing
Greetings, Jan.

Hi all, great forum-topic on the gps-devices and good to see so many others trying this setup of Jan. So I'm going to join the experiment as well. Initially with ideas to customize a lot, but I think I have to start modest and just see if I can get everything to work with the recommended hardware.

I still have a working GT31 and also have a Gyro1 from Raymond (NL, I'm from NL as well).

I have alway used both devices in a protected bag on the upper arm.

I love the size, accuracy and the info on the Gyro1, but the readability of the e-paper is ssuperior. Also the wireless capabilities are nice. I'm hoping to build one and try some experiments. I might need some help from this community but looking at the responses, that should be OK.

Really enjoyed the topic on waterproofing a case. Never realized it would be this tough. If possible I would like to construct something myself as well. For now I start with the purchased case as the others.

Parts should arrive in 2-3wks. I will post updates on the progress.

Cheers, Simon

Not so bad with the delivery times from China. I just got the LilyGo T5 today and I got enthusiastic. First check if it was alive through USB, check. Got the flash tool, flashed the program of Jan and booted again. No change, but I forgot to check the files after selecting then (with right BN display). Then it became alive. Sdcard was not FAT32 formatted, did that and updated the config file with my home SSID and right password and the wifi went live. Tried to connect with WinSCP FTP user/pw both esp32 and bang... could read and write. It went really smooth. Connected an old Hubsan lipo of 3.7V 500mA with the included connector and it was live unplugged. Great! Didn't expect it was so easy... Great experience so far.
Now wait for the rest of the parts (Beitian BN280, read switches, waterproof box, wireless QI charger and battery. But at least this initial part is done. Thanks to Jan for the great documentation ??????

In the meantime I also got the battery and charger. The charger can with a USB connector so it didn't require soldering, however it's pretty short so I guess I will extend it when the boxes arrive. Nice that I can transfer the power of my Samsung Galaxy wireless to the gps device.
Software wise, I'm still a bit confused. Since it is e-paper it is hard to tell if it is on or off. The slight movement in the display will give it away I guess. But a nice closing screen or a simple goodbye or message apply magnet to start would be more friendly.

I haven't played yet with the speed views (waiting for my BT280 to arrive). What I really likes about the Gyro is 1 vieuw with 2 columns and 6 lines. Left column contains the average of 5x10sec runs and the 5 best 10sec runs individually and the right column the 2sec, previous run, alpha, 250m, 500m and nautical mile. It's so stimulating to see that one of your previous runs contributed to the average 5x10sec.
I would love to see that added. So I might dive into this later as well. Would be nice to know where to start. Obviously it is compiled, but I don't think the sources are available. No need for the whole thing but would be nice if part of the program blocks could be co-developed for the benefit of all. Perhaps the options of the block could be controlled via the config.txt

Is everyone just buying the parts from Ali express? I've never used them is all.

thanks Shannon.

Yes Ali express

Here in Belgium are Ali express and Banggood the possible suppliers. We also have local suppliers which can deliver the same items, but at a higher cost. But delivery times are then less then week. For Aliexpress/Banggood, we have shipping times between 2 and 6 weeks. Therefore, the prices are low and the shipping cost also. Never had a lost shipping (over more then 100 items). If you use Paypal, you can open a dispute if something get lost/no delivery. They will pay you back if the issue was with the supplier.

Thanks Elmo and rp6conrad. I've just placed an order for the bits. Fingers crossed they don't take too long to arrive and I can figure out how to assemble it!

shannon.

One of my windsurf mates has made a beautiful sealed housing for the diy-logger ! Water testing is planned....

What are the minimum dimensions for the case? A GoPro 9/10 is about 71x55x34. Would a waterproof housing for that work?

Unfortunately, a standard action cam case is too small. In the attached picture, the micro SD card is not mounted, this makes it even worse !

I haven't been able to find the files to put on the sd card/board - the code Jan so thoughtfully wrote. I've looked in all three manuals and this thread and can't find a link. Maybe someone can point me to them?

Once I find them I have to figure out how to do all this on a mac - is it possible?

FYI, I found a way to shorted the micro sd card via an adapter so it doesn't stick out at all. Just a basic micro sd extender from amazon that I carefully shortened with a razor without cutting the ribbon cable that was adhered to the top of the g10. EDIT: link www.amazon.com/dp/B07QXPG8HG?psc=1&ref=ppx_yo2_dt_b_product_details

Manuals: can't find the code in these.
docs.google.com/document/d/1j86kj3bNMID3sHCRT7QTYyrL7IHeQnGPec1LajsDfB4/edit

docs.google.com/document/d/1XJD6BV1Xay4nXo0cDuo_IOtxC_f1LyG7DE7X6KGlAB0/edit#

docs.google.com/document/d/e/2PACX-1vQ7kR5tCX906ER15K-lsmmVZKAK3O7mNz37po92eMhcj7J5gWulg-c2lgcQfTCDV8037NtgWirQbFev/pub?utm_source=seabreeze.com.au

PM Jan with your email adress and he will send you the software

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lwalker said..
What are the minimum dimensions for the case? A GoPro 9/10 is about 71x55x34. Would a waterproof housing for that work?

A friend of me has put a lot of effort to make the logger as small as possible, and watertight ! His approach was :
Soldering the SD-card (6 connections)
Smaller battery of 800 mAh instead of 2000 mAh
Beitian BN220 GPS (20*22mm) instead the BN280, mounted flat under the T5-board.
Acrylic case which is glued out of 3mm acrylic
No reed switch, but waterproof switch. Water testing until now is positif, seems to be working fine !

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JohnnyTsunami said..
Once I find them I have to figure out how to do all this on a mac - is it possible?

Everything initially can be done on a Mac. The limitation however is the day to day wireless data transfer (downloading your run data) via FTP doesn't seem to work with Mac. I tried many different FTP software with Mac and all fail. Windows FTP works fine. Jan thinks its something to do with added security features on Mac. Currently I use my daughters old school HP stream which cost about $300 6 years ago and works fine..however it means I need to lug 2 laptops around if not sailing at home. Might be able to use PC emulator on Mac(parallels etc) but haven't tried. If anyone finds out how to connect it would be great.

On a Iphone (IOS15.3), the ftp is functional ! I used FTPManager : apps.apple.com/us/app/ftpmanager-ftp-sftp-client/id525959186
Greetings, Jan.

ok Jan, great news..will try it soon. Other news, my first epoxy'd prototype died today. It's been a loyal servant for 59 sessions. Has symptoms of not reading SD card. In my haste to epoxy the units in I didn't realise I'd forgotten to add a leash mount on the original units until I'd poured in the epoxy. So I added one after the fact with a bolt through the epoxy fill hole. Seems as if over time the bolt has slowly caused the epoxy to crack and allow moisture in to the SD card and corrode it. There is a pretty clear path for moisture to travel along which you might see in the attached photo. (Interestingly despite many crashes the leash has never been called into action..the elastic is a fairly robust attachment method but for sure the leash gives peace of mind)

It seems to fit in the (giant) GoPro 9/10 case. This is a knockoff I got for $12. I'll have to do some swimming pool tests with it to confirm it's really dry before using it with the GPS.

You are a genius ! The GoPro Hero 9/10 is indeed a lot bigger then the older GoPros, I didn't knew that. The Hero 10 is 50.8*71.8, and the complete T5 fits wonderfull. Also the prices for the cases are reasonable, for Belgium ca 10? (Ali express) : nl.aliexpress.com/item/1005003299943749.html?spm=a2g0o.productlist.0.0.66bf5c292SwgGS&algo_pvid=7d76dd76-297b-4186-aec0-4061ff1b116d&aem_p4p_detail=202202111014351232090246340000128314988&algo_exp_id=7d76dd76-297b-4186-aec0-4061ff1b116d-1&pdp_ext_f=%7B%22sku_id%22%3A%2212000025092050155%22%7D&pdp_pi=-1%3B9.47%3B-1%3B114%40salePrice%3BEUR%3Bsearch-mainSearch
I'll give it a try !

Had a bit of a win in regards to downloading data without a PC.

If you use a normal Wifi connection like your home wifi, FTP manager seems to work (tested for iPhone 8 and 11). It does not seem to work using iPhone as a hotspot which means can't download in the field, at least I can't. You could change the config file ahead of time to your hotel etc wifi but if you've epoxy'd your units like me that requires a PC. My iPhone 8 doesn't seem to allow FTP Manager connection in AP mode although Jan's iPhone 11 does.

The work around is quite elegant but requires having two units (at least I think its elegant but there is currently a catch). You configure each unit to log on to the AP of the other unit. i.e. change the config.txt file on the SD card on the unit you want to download so the SSID is "ESP32A" and password is "password" (The catch is you probably only want to change one units config at present for reasons below)

Start with both units off
A. You then turn another unit on (one you don't want data off) and then reapply the magnet on startup when the display says so, so it enters AP (Access Point) mode. The display shows ESP32AP password. This means it is acting as a Wifi hotspot.
B. You then turn the other unit on that has the config setup to look for the ESP wifi. It then logs on to the other units Wifi and now if successful both units display independent IP addresses. In my case the AP unit displays 192.168.4.1 and the 2nd unit (the one you are going to get data off) displays 192.168.4.2
C. Then you logon to the ESP wifi with your iPhone (I am sure works same with Android but Android probably works natively)
D. log to 192.168.4.2 with FTP manager (port 21, user: esp32, password: esp32).
E. All the files are then displayed and you can download/delete etc at good speed for immediate upload to KA72, GPSSpeed reader etc using just your phone or send them to your Mac with airdrop etc. (a 2 hr session took about 10 secs to go from unit to phone to Mac)

Now an interesting thing (the catch) occurs if you change 2 units to look for the ESP Wifi. (i.e. change both config.txt files)
The steps are the same until step D. Once you have logged onto the ESP Wifi with your iPhone BOTH units now display the same IP address....they both display 192.168.4.1 Even more interesting is now both units files show using FTP manager and can download/delete both units data.

The catch is I was using version 5.4 and after a bit of playing to confirm the above I managed to lock up the device that was started in AP mode so that it could not be turned off using the reed switch. The iPhone and other unit could still logon to its Wifi but no data transfer was possible.

I thought I would have to run the battery to shutdown at 2.8V in order to get a restart but after exactly 3000 secs reported session time the locked unit reverted to GPS mode and allowed a normal shut down.

I am sure Jan can advise further what might be happening here but at least there seems to be a reasonable chance to download without a PC. I haven't tried above trick with Mac but will do so later.

BTW, I don't recommend the more expensive M21 version of the T5. For some dumb reason, I figured higher temp range just meant better, but there seems to be some differences that mess up the text sizing. Either that, or the unit I got was just bad. The wifi never did work.

Lastly, verify the wiring on the GPS cable. On mine, Red and White were reversed.

Big thanks to Jan for helping with troubleshooting this stuff with me.

The issue with the screen overflow is caused by the resolution of the e-paper ! After a bit research, I found out that the resolution of the H480 and H239-02 is different from my units (H239 / H239-01). So, my advice to go for the cheapest, this is the H239 or the H239-01. I have no clue why the Wifi isn't working on your unit, maybe just bad luck and DOA (dead on arrival).
I am still working on the ftp function for Iphone / Android, but this can take some time.....
Details about the used e-papers can be found here : www.good-display.com/product/229.html

Agree with Iwalker re the M21 not recommended. My first unit was M21 thinking the better temperature range would result in more robust unit. Within 1 minute I'd managed to fry it with the screen going black. This may have been because I was driving a BN-880 GPS (larger current draw?) or just being useless. My 4 other units been B74 version and had no issue with them.