Hobbytronics Keyboard host I2C issue


I have a Hobbytronics keyboard USB host IC connected to my UNO.


All I am getting is ‘10’ printed on the screen every 5 seconds. I have checked the I2C bus with a scanner and it pings back 0x29 (41), so that should be correct.

If you mash an attached keyboard (the led on the 28 pin IC illuminates to show correct connection of the keyboard), you get a random number returned. Never the correct one or the letter you pressed.

This is the demo code from their webpage. I have emailed their tech help, but no response yet.

Any ideas?

** Wire Master Reader of Hobbytronics USB Host Keyboard
** Created 24 Oct 2013
** This example code is in the public domain.
** www.hobbytronics.co.uk

#include <Wire.h>

const int  adc_address=41;   // I2C Address

char keyboard_data[80];   // Array to store keyboard values   

void setup()
  //Send settings to ADC_I2C device (optional)
  Wire.begin();              // join i2c bus (address optional for master) 
  //Start Serial port
  Serial.begin(9600);        // start serial for output

void loop()
  unsigned char i;
  char keyboard_chars;

  Wire.beginTransmission(adc_address); // transmit to device
  Wire.write(1);                       // ask how many characters are in buffer
  Wire.endTransmission();              // stop transmitting  
  Wire.requestFrom(adc_address, 1);    // request 1 bytes from slave device
     keyboard_chars = Wire.read();

  Serial.println(keyboard_chars, DEC); // print number of buffer characters
  Wire.beginTransmission(adc_address); // transmit to device
  Wire.write(0);                       // get keyboard characters
  Wire.endTransmission();              // stop transmitting  
  Wire.requestFrom(adc_address, keyboard_chars);    // request characters from slave device
     keyboard_data[i++] = Wire.read();
     keyboard_data[i] = '\0';

  Serial.println(keyboard_data);       // print the character  

  delay(5000);                         // Wait 5 seconds

just noticed it fires back '10' all the time, but if you press and hold the keyboard letter down, then it returns the letter pressed about 8 times.

Trying serial instead of I2C.

It says the bat54 Diode is to protect pin 2 of the PIC IC. Would that not mean the RX and TX are back to front on the legend on the left (processor connections)

Can't find a data sheet for that PIC chip. Is pin 2 definitely the RX pin?