PbHub 1.1 on STAMPLC - Couldn't find Pbhub on PortA

bensonwhlee

I am using STAMPLC and have all function included the PWR485 are normal. However, I purchase a PbHub to use as a extended input for buttons. I cannot connect the PbHub on PortA or PortC on STAMPLC.
I follow the sample code as follow in setup:
#include "M5UnitPbHub.h"
M5UnitPbHub pbhub;
void setup() {
Serial.begin(115200);
if (!pbhub.begin(&Wire, UNIT_PBHUB_I2C_ADDR, 2, 1, 400000U)) {
Serial.println("Couldn't find Pbhub");
while (1) delay(1);
}
}

void loop() {
Serial.printf("ch:%d adc:%d\r\n", 0 , pbhub.analogRead(0));
delay(1);
}

The following is the response on Serial Monitor:
Couldn't find Pbhub

E (1982) i2c.master: I2C transaction unexpected nack detected
E (1983) i2c.master: s_i2c_synchronous_transaction(924): I2C transaction failed
E (1984) i2c.master: i2c_master_multi_buffer_transmit(1186): I2C transaction failed

Wirings and functions are correct, G1 and G2 can get analogue and digital data I/O as normal. Any hints to solve the problem. I have write a simple I2C scanner program on Port A G2, G1 pin, there was response from Address 0x61, but Pbhub library cannot read data from Pbhub

felmue

Hello @bensonwhlee

I think you need to use the M5StamPLC library together with M5Unified and M5GFX libraries for it to work properly.

Please find an example here which works for me.

Edit: if you don't need M5StamPLC specific functions then it should be sufficient to add the following line to your setup code:

Wire.begin(2, 1, 400000U);

Thanks
Felix

bensonwhlee

@felmue
Thank you Felmue,
By testing the Wire interface and M5UnitPbHub seperately, I finally got response from the PbHub. I'm not sure what cause the problem. When I used your sample with the minimal code, the PbHub responsed and got analog data back after serval reset or unplug/replug the PortA cable. But it is not consistency working after each program download.
In my more complicated program with SD, PWR485 , M5StamPLC.Display , the PbHub did not work at all. But if I just put in I2C scanning code together with my program, there is response from PbHub that address 0x61 was found.
I think the problem is the command:
pbhub.begin(&Wire, UNIT_PBHUB_I2C_ADDR, 2, 1, 400000U) and
Serial.printf("0:%d 1: %d 2:%d 3:%d 4:%d 5:%d \n",pbhub.analogRead(0), pbhub.analogRead(1), pbhub.analogRead(2), pbhub.analogRead(3), pbhub.analogRead(4),pbhub.analogRead(5));

felmue

Hello @bensonwhlee

try adding a delay(500) before calling pbhub.begin(). My above linked code fails to initialize PbHub without a delay.

Thanks
Felix

Slarck

@felmue said in PbHub 1.1 on STAMPLC - Couldn't find Pbhub on PortA:

Hello @bensonwhlee

try adding a delay(500) before calling pbhub.begin(). My above linked code fails to initialize PbHub without a delay.

Thanks
Felix

“Thanks @felmue, that’s a helpful tip about the delay. I’ve seen similar I2C issues where peripherals don’t initialize properly without a short wait after boot. Good to know it applies to the PbHub too!”