I recently recently received a pair of these modules from Spark Fun in order to help a friend who was having trouble getting them working. Neither of us had any experience with SPI.
Well, getting these to work with a Picaxe is not for the faint of heart or those that give up easily.
I chose the 20x2 and after at least 40 hours of fiddling I have the pair communicating nicely using one as a dedicated transmitter and the other as
a dedicated receiver. This is because the transmit section on one of the modules doesn't work due to me accidentally connecting the module and one of the 20x2s to 11 volts instead of 5v. The picaxe survived, but the PTX section on the NRF24L01+ did not.
In any case at 2.4 Ghz, a chip antenna and a 1 mbps air data rate the range is adequate for around the house and adjacent out buildings. Max output is 0db. An SMA with a whip might improve range a bit. Changing the air data rate to 250 kbps may also improve range at the expense of a slightly higher power consumption.
These are nice units with a lot of features and work well once the data sheet is deciphered and understood. Packet size is up to 32 bytes and CRC is automatic in what they call Enhanced Shock Burst mode. One PRX device can communicate easily with up to 6 PTX devices in a mini network that Nordic calls "Multicast". There are 126 selectable RF channels in the range of 2.4 to 2.4835 Ghz. Data can be stored in the TX FIFO and transmitted later if needed. There are 3 separate 32 byte TX and RX FIFOSs and the Pins are 5 v tolerant so you dont have to worry about frying the modules with 5v HSPI data. The transceiver module generates an "interrupt" signal when data is successfully sent, or received or if there are to many retries. The micro can read the status register to see which of these occured and then take appropriate action. So these modules are quite sophisticated but at the expense of more complex code than the typical serial out serial in modules.
If anyone in interested I will post some Picaxe code to show how I got these units to communicate using HSPI. I also wrote some routines that will dump out the settings of all the registers and send them out to the Picaxe serial terminal. And other sub routines that do a lot of the necessary functions and housekeeping. So if anyone is interested I will post the (commented) code I have to possibly make it easier for others to get these nice units working with a Picaxe.
Goeytex
Well, getting these to work with a Picaxe is not for the faint of heart or those that give up easily.
I chose the 20x2 and after at least 40 hours of fiddling I have the pair communicating nicely using one as a dedicated transmitter and the other as
a dedicated receiver. This is because the transmit section on one of the modules doesn't work due to me accidentally connecting the module and one of the 20x2s to 11 volts instead of 5v. The picaxe survived, but the PTX section on the NRF24L01+ did not.
In any case at 2.4 Ghz, a chip antenna and a 1 mbps air data rate the range is adequate for around the house and adjacent out buildings. Max output is 0db. An SMA with a whip might improve range a bit. Changing the air data rate to 250 kbps may also improve range at the expense of a slightly higher power consumption.
These are nice units with a lot of features and work well once the data sheet is deciphered and understood. Packet size is up to 32 bytes and CRC is automatic in what they call Enhanced Shock Burst mode. One PRX device can communicate easily with up to 6 PTX devices in a mini network that Nordic calls "Multicast". There are 126 selectable RF channels in the range of 2.4 to 2.4835 Ghz. Data can be stored in the TX FIFO and transmitted later if needed. There are 3 separate 32 byte TX and RX FIFOSs and the Pins are 5 v tolerant so you dont have to worry about frying the modules with 5v HSPI data. The transceiver module generates an "interrupt" signal when data is successfully sent, or received or if there are to many retries. The micro can read the status register to see which of these occured and then take appropriate action. So these modules are quite sophisticated but at the expense of more complex code than the typical serial out serial in modules.
If anyone in interested I will post some Picaxe code to show how I got these units to communicate using HSPI. I also wrote some routines that will dump out the settings of all the registers and send them out to the Picaxe serial terminal. And other sub routines that do a lot of the necessary functions and housekeeping. So if anyone is interested I will post the (commented) code I have to possibly make it easier for others to get these nice units working with a Picaxe.
Goeytex
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