bought two TTGO T-Beam ESP32 868/915Mhz. I was able to flash firmware-0.2.3 and both units boot up and I can connect my phone via the app / bluetooth. The issue is I get a “GPS : (” on one device whereas the other gives me a “GPS: ok”. Is there any way to test the gps or does this mean its toast and I need to do an rma. I’ve tried doing a manual erase_flash and reflashed the firmware twice but the one unit keeps giving me the same thing.
Do you get any life out of the red PPS LED? Or use a serial terminal set to 115200 baud and see if the debug messages say anything of use.
Hello killeramoeba & Dafeman
When the screen says GPS 
on Tbeam, then the GPS hasn’t got a fix yet or maybe there is no communication with GPS at all.
Once the GPS has a fix, the red led will flash once a second for a few times, and the O-led will say ‘GPS ok". Afterwards, the red lights won’t flash anymore, but rather quickly every time the GPS is searching when it lost its fix, and again 2x/sec when the fix comes back or when the module wakes up after sleep, I assume.
(My onboard NeoM8N seems to work that way; if yours is M6N it shouldn’t differ much)
If you’re indoors, you should be close enough to a window or the GPS won’t see any satellites.
Given your GPS is working: in serial monitor, first you should find “connected to GPS successfully, TXpin=” followed by the GPIOpin for your board’s GPS-TXpin (TTGO-Tbeam v1.0 will be 12; but for version 0.7 this would be 15).
You may also find a message that the GPS provided time info, but it doesn’t mean that it’s got a position fix. The time info comes from the GPS’ internal RTC which is battery backed up.
Once there is a fix, the serial monitor will display non-zeo GPS cordinates.
If you don’t see any messages from the GPS in serial monitor, then you should check if you have loaded the right .bin file for you r T-Beam: T-Beam exists in 2 versions; below V_0.7 needs .bin file for V_0.7 ; starting from V_0.8 and higher you will need to load V_1.0 .bin file. Good luck!
1 Like
on cold boot board instantly shows "gps: ( " where as on the other board it shows “gps:ok”. They both have neo m6 gps on a v1 board. I’m running firmware-tbeam-US-0.2.3.bin
hi
I see you’ve got a Tbeamv1.0 as I do but mine has NeoM8N. I ran into GPS problems and have been looking for the cause for 2h this afternoon.
Then I realised that the previous 2 days I tested my boards downstairs and evey time my gps found a fix very soon. Now it didn’t, until I took off the ipex connector and mounted a real gps antenna on it which is sniffing outside…Perfect gps-fix from the start !
So it might be that on your other board there is just a bad gps antenna connection. Might help to take it off and clip it back in. The oled will show a grumpy gps until you renew its screen (push the userbutton or let it sleep and wake it up).
But already after restart, you might see an error msg ‘cannot find bidirectional gps’, as i did, and 2 seconds later, serial was showing real cordinates!
log (app v2.0.4 installed via Google Play Store update on Blackview phone Android 7)
=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2020.04.07 17:25:12 =~=~=~=~=~=~=~=~=~=~=~=
ets Jun 8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:8896
load:0x40080400,len:5828
entry 0x400806ac
booted, wake cause 0 (boot count 1), reset_reason=reset
I2C device found at address 0x34
axp192 PMU found
I2C device found at address 0x3c
ssd1306 display found
done
Meshtastic swver=0.2.3, hwver=1.0-EU865
Turning on screen
chip id detect 0x3
Detect CHIP :AXP192
OUTPUT Register 0x5f
AXP192 Begin PASS
DCDC1: ENABLE
DCDC2: ENABLE
LDO2: ENABLE
LDO3: ENABLE
DCDC3: ENABLE
Exten: ENABLE
DCDC1: ENABLE
DCDC2: ENABLE
LDO2: ENABLE
LDO3: ENABLE
DCDC3: ENABLE
Exten: ENABLE
SRC REG:0xc4
Charging enable is enable
Charging target-voltage : 0x2
end when the charge current is lower than 10% of the set value
Charge current : 700.00 mA
enable [0x40]val:0xdc
enable [0x41]val:0xff
enable [0x42]val:0x3b
Read RTC time as 1 (cur millis 1551) valid=0
ERROR: No bidirectional GPS found, hoping that it still might work
RadioConfig reset!
Loading saved preferences
Warn: devicestate is old, discarding
NODENUM=0x40, dbsize=1
Starting meshradio init…
IRQ flag mask 0x0
Set radio: name=Default, config=3, ch=6, txpower=23
new gps pos lat=44.352563, lon=4.411676, alt=320
got gps notify
Sending position to mesh
2 Likes
yeah I left both on the second floor of my house near a window and the second one now has a “GPS: ok”. I took the antenna off before hand and reseated it. But I did notice it had a garbled screen after a reboot but seemed find after another reboot. I think its got some weird hardware issues going on. Which app did you try, Putty?
Yes, Putty lets you log in the background on a serial port X while you can program another board on another serial port Y.
Yea Putty, Arduino IDE, Platform IO all have a useful serial terminal.
Thanks Erik for helping others!
1 Like
I use miniterm piped to tee to capture logs:
miniterm - 115200 | tee log1.txt
Different log for second one using - (dash) in miniterm args makes it list them then you choose the port name eg. /dev/ttyUSB0 , in case they are changing. So i have one terminal window for each. Using tee means you are not limited by size of terminal scroll buffer.
Gps can take a long time to cold start, the red led seems to flash less less on recent builds? I thought one of mine had issues for a while. I found that propping up ttgo in a cup so lora antenna and gps antenna pointing up, you can have usb connected, still. i stick gps antenna on side of 18650 holder near lora antenna i think all the brass acts as a ground plane.
so I spoke to the oem and it looks like they shipped me the wrong ttgo’s. Mine are labled 868/915mhz but are really 433mhz. I have my ham licence so thats kind of a good thing and I should get far more distance . Now I just need to reflash and hope for the best.
So i did a full reflash but still the units won’t see each other. Is there an IC or something on the board that I can confirm that my TTGO T-Beam is the one they say it is?
I have working pair of ttgo 433Mhz, I bought 433Mhz because I figured it may be longer distance. I do my own build using vscode - last time I flashed a week or two ago it reports Meshtastic swver=0.0.0, hwver=1.0 - US which means US 915Mhz - but its not really, it is actually EU433, tested range to almost a mile in an urban environment, it may have gone further. I have confirmed its really 433Mhz using an rtl-sdr.
@killeramoeba as you have ham license do you know if the antenna can be optimised and still be reasonably compact? I have taken off the plastic to inspect the antenna and inside its a coil 20.5 turns, these a small gap between each turn
2 Likes
Hi Scott, you I think that string is wrong with the new build system (though the settings are correct). See this bug, which if no one else gets to it I’ll get to it sometime in the next couple of weeks:
Which firmware type did you use v1 EU433?
Far as making a more compact antenna a coiled monopole (stock antenna) is about the smallest unless you go with some sort of printed phased array. Considering how little power these have I’d stick to a 1/4 wave monopole or dipole with a ground plane.
I am building myself - I set hw_version = EU433 in platformio.ini, From the releases zip file it would be firmware-tbeam-EU433-0.2.3.bin for version 1.0 ttgo t-beam.
1 Like
Hello Scott, could you please share your compiled firmware? Thank you.
Hi Geeksville, I use custom board with RA-02 sx1278(ttgo t-beam gpio), none of EU 433 firmware doesn’t broadcast data. If I flash US firmware, it start to broadcast data at 916.04 Mhz(weak signal, because RA-02 sx1278 410-525 Mhz). I tried CN, JP, EU865, EU433- no radio signal. With any Arduino examples it works perfectly on 433Mhz. Maybe something wrong with precompiled bin’s for other frequencies?
I emailed my firmware to you which is for t-beam 1.0, IDK whether not having axp192 would affect you, does it work? on my sx1278 modules when i flash US frequency by accident it does not work at all even with the two boards inches away from each other. I have used a rtl sdr dongle with mine and can see the signal at 433Mhz
1 Like
Hi Scott, I detect weak signal with SDR on US frequency. In email I recieved “Attachment firmware.bin is missing”. Can You Resend an email. Thant you.
2 Likes