TWOG/add i2c1

It can be handy to have a second I2C port on the TWOG v1.00 or Tiny v2.11. This allows to separate flight sensitive sensors (e.g. IMU) from payload sensors.

Add 2nd I2C port to TWOG/Tiny on ADC2/J8

ADC2/J8 can easily be modified to have the same pinout as the original I2C/J6 port.

remove R12
replace R13 with a 10k resistor
cut the trace between R13 and R15
connect the (then) open end of R13 with 3.3V at R17
connect J8_IN_ADC_6 with J7_BOOT (SDA1)
connect J8_IN_ADC_5 with J2_CTS (SCL1)
secure the thin wire with small dots of hot glue

The original I2C/J6 is i2c0 and ADC2/J8 becomes i2c1.

Modification TWOG/Tiny

Add 2nd I2C port to TWOG/Tiny on J11/IRH

J11/IRH can be modified to carry I2C signales. Make sure you provide 5V if needed.

add a new 10k resistor on the 3.3V side of R17
cut the trace at J11_IRH_IRH_1 (pin 4)
cut the trace at J11_IRH_IRH_2 (pin 3)
connect J11_IRH_IRH_1 with other side of new 10k resistor
connect other side of new 10k resistor with J2_CTS (SCL1)
connect J11_IRH_IRH_2 J7_BOOT (SDA1)
secure the thin wire with small dots of hot glue

The original I2C/J6 is i2c0 and J11/IRH becomes i2c1.

Modification TWOG/Tiny

Add 2nd I2C port to Tiny on Download/J7

On the Tiny Download/J7 can also be modified to have I2C.

cut the trace between J7_LPC_TXD0 and the IC5/LPC2148
add a 10k pull-up resistor to J7_+3.3v
connect other side of the new 10k to J7_LPC_TXD0
connect J7_LPC_TXD0 with J2_CTS (SCL1)
secure the thin wire with small dots of hot glue

The original I2C/J6 is i2c0 and Download/J7 becomes i2c1 (J7_LPC_TXD0 = SCL1, J7_BOOT = SDA1).

Modification Tiny