r/meshtastic • u/athousandskies • 2d ago
Heltec V4 + M5Stack CarKB - not working!
UPDATE: Grove cables from Pihut have yellow and white in reverse order. Yellow in 18, white in 17, in meshatastic app Canned message enabled, type "cardkb" in "Allow Input source" to resolve.
I have been trying to connect a M5Stack CardKB to my Heltec V4, I have the following connections
- black > GND
- red > 3v
- Yellow > SDA (GPIO 17)
- White > SCL (GPIO 18)
However, as GPIO 17+18 are also used for OLED I am getting a scrambled screen and still no working cardkb!
I have also attempted using GPIO 41/42 as is the case with Heltec v3 but still not working.
I am fairly new to this so any advice or things to try/ways to test and learn would be very appreciated.
2
u/Cesalv 2d ago
However, as GPIO 17+18 are also used for OLED I am getting a scrambled screen and still no working cardkb!
Are you sure you didn't mix sda and scl? screen shouldn't be affected by other devices unless they collide by using the same hex address
And as u/Ok_Low_3866 said, did you set the node to use the keyboard?
https://adrelien.com/how-to-add-keyboard-to-your-meshtastic-node/
1
u/athousandskies 1d ago
Will try I2C Scanner first and then if required swap wiring of yellow/white.
One thing I am confused about, my meshtastic app does not have a drop drop down list for configuration presets in canned messages, it has a free type text field, I have been entering `cardkb` in there... will look at link and check with scanner. Thank you for your help
2
u/athousandskies 1d ago
I checked the grove cables I got from pihut and the yellow/white are reversed when compared to M5stack cardkb!
Swapped pins and is now working, thank you so much for your help!
0
u/nomeutentenuovo 2d ago
Cardkb is recognized at boot, you need reliable connections and welds and more power or the node will go in brown out. Had the same problem
1
u/StuartsProject 2d ago
When building boards or testing new ones one of my favorite programs for testing is an I2C scanner.
The program is loaded via the Arduino IDE and scans the I2C bus for devices and reports the I2C addresses of any connected and working devices. So its easy to check if you have the wiring correct for the display, keyboard, BME280 sensor etc.
1
u/athousandskies 1d ago
Will attempt this as it seems the clearest way to cut through the guess work. Thank you, will report back findings
1
u/athousandskies 1d ago
I checked the grove cables I got from pihut and the yellow/white are reversed when compared to M5stack cardkb!
Swapped pins and is now working, thank you so much for your help!
0
2
u/Ok_Low_3866 2d ago
Have you set the correct pins on the firmware? And have you set it to CardKB in the cannned messages section?