ArduinoMania

Prototyping my home automation system i ran into troubles. I can’t make work two SPI devices on Arduino Mega. One is an ethernet shield based on enc28J60 made by ekitszone, other is a small module based on Nordic’s nRF24L01+ transceiver. Spot the problem without an oscilloscope was really frustrating, oscilloscopes are not hacker’s best friends for nothing. After checking and rechecking solder joints, my code, astral conjunctions, finally i found the real problem. Trivially MOSI and MISO on ethernet shiled are reversed. Detaching the shield from Arduino and using a breadboard to invert MOSI (pin 51) and MISO (pin 50) make everything work (to be true, my code doesn’t use ethernet yet but the transreceiver works like a charm now). I don’t know which batches are affected but if you are in trouble with these shield using enc28J60 datasheet and a tester try to figure out if this is your situation. Happy hacking.

Prototyping my home automation system i ran into troubles. I can’t make work two SPI devices on Arduino Mega. One is an ethernet shield based on enc28J60 made by ekitszone, other is a small module based on Nordic’s nRF24L01+ transceiver. Spot the problem without an oscilloscope was really frustrating, oscilloscopes are not hacker’s best friends for nothing. After checking and rechecking solder joints, my code, astral conjunctions, finally i found the real problem. Trivially MOSI and MISO signals of SPI bus on ethernet shiled are reversed. Detaching the shield from Arduino and using a breadboard to invert MOSI (pin 51) and MISO (pin 50) make everything work (to be true, my code doesn’t use ethernet yet but the transreceiver works like a charm now). I don’t know which batches are affected but if you are in trouble with these shield using enc28J60 datasheet and a tester try to figure out if this is your situation. Happy hacking.