Archive for October 2009
When I start the PCB design I’ll think that some modifications can be done, like that a more power MCU and other goodies, like wireless communication.
Today most of DIY electronics projects use ZigBee or XBee for wireless communication. But i like to use a very low power device. I think that use one of the devices from Nordic, like nRF2401 or nRF24L01+ is a good choice. They aren’t full-duplex, but it’s don’t become a problem to me because most of I want is for telemetries, where the robot send data and receive in distinct moments.
This is nF24L01+ characteristics:
• 11.3mA TX at 0dBm output power
• 13.5mA RX at 2Mbps air data rate
• 900nA in power down
• 26µA in standby-I
• On chip voltage regulator
• 1.9 to 3.6V supply range
• On-air compatible in 250kbps and 1Mbps
with nRF2401A, nRF2402, nRF24E1 and
• Low cost BOM (Bill Of Materials)
• 5V tolerant inputs (everyone like devices with tolerant inputs)
After much headache I’ve finished the design of the two boards. I’ve made some mistakes with the design and some of mistakes I only know when the boards arrive to me. I’ts very frustrating…
Some of these mistakes besides on design with components that you don’t have in your hands or that you can’t find to purchase. This is a tip for everyone starting a new design: only use components that you really now where obtain. Some parts may appear to be easy to find, but they don’t.
Because some of that mistakes the controller board is finished but the motor board not. View the pictures:
This a video with the board in test.
The motor board, with the motors, h-bridge and other parts are in late because a great mistake: one of the connectors between boards are reversed (Duh!).
Was soon the motor board comes I’ll post the final mount and tests.
Next post I’ll show circuit details. Bye.