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Topic: Wireless sensor node with MSP430G2553/NRF24L01+ (Read 3432 times) previous topic - next topic

Wireless sensor node with MSP430G2553/NRF24L01+



I set out to design a wireless sensor PCB that could be inexpensively prototyped in quantities of 10. NRF24L01+ modules are exceedingly cheap (~$10 for 10), use very little power, and have sufficient range for most indoor projects. Low power MSP430 microcontrollers make an ideal partner for battery powered applications. I settled on the MSP430G2553, but the MSP430G2452 can be substituted whenever hardware UART is not required.

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Github repo

I'm happy to donate a few pairs of these to the free PCB drawer.

Re: Wireless sensor node with MSP430G2553/NRF24L01+

Reply #1
Home thermostat project

Magic Mote + DHT22 broadcasts to Magic Mote + latching relay.

Re: Wireless sensor node with MSP430G2553/NRF24L01+

Reply #2
Another home "improvement" project - automatic lights in the basement laundry room. We often go in and out carrying a laundry basket so it's convenient not to have to hit a switch. And once in a while it might save a bit of electricity turning the lights off when nobody is in the room. I have fixed up the PIR sensor in a blue PVC "new work" box in the rafters. From this position, it triggers immediately when the door is opened and retriggers when there is movement in the room. I am experimenting with placement because I am concerned that the furnace turning on and off might also trigger the sensor.

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As with the furnace relay, the PIR sensor is powered from the door bell transformer. Once I am happy with its placement, I will hook up a Magic Mote to the PIR sensor, powering it from the sensor's own 3V supply which is broken out to the retrigger select jumper header. The Magic Mote will switch the lights via a relay board and handle the timing, turning the lights off after 5 minutes or so. There is some ambient light from a little window so I will probably mount a photodiode on the analogue pin to disable the lights if it is sufficiently bright. Lastly I will replace the existing toggle switch with a momentary switch that will manually override the sensor and turn the lights on for a full 15 minutes. And the NRF24L01+ module on board the Magic Mote will report everything back to the BeagleBone webserver so that everything gets logged on Xively.

That's the plan anyway. :)

Re: Wireless sensor node with MSP430G2553/NRF24L01+

Reply #3
Here is Version 2 of the Magic Mote PCB. The tactile switch is more accessible at the side of the board, the programming/serial header is now IDC6 compatible, and there is improved isolation of the ground plane under the watch crystal.