The initial code commit for wireless programming was a little sluggish and the performance wasn’t very good. I had to add delays to make sure everything was synch-ed and the protocol was working. The result was a rather slow wireless upload of a new sketch, especially if it was a large sketch. But it worked…
Today I worked on improving the protocol and was able to cut down the over-the-air upload time by a factor of ~5. The gains are mostly from improved serial communication. This will still take about twice as long as normal sketch uploads by means of an FTDI adapter. For instance, a 9,8Kbyte sketch takes me about 11 seconds to upload directly to a Moteino using an FTDI cable; wirelessly programming that same sketch takes about 22 seconds. Not bad given how involved the whole handshaking protocol works. And much better than almost 1 minute with the old code. So I’m classifying this new release as a beta. More improvements or bug fixes might be added later, but it’s definitely a functional release. I’ve uploaded different sketches of around 10KB several times without a glitch.
The wireless sketches examples (gateway and node) and the python script are in their github repo. The SPIFlash library was also updated (the WirelessHEX part of it), so get latest before you try this.
As mentioned before, the target node of the wireless programming protocol will need to have an SPI Flash chip attached (if they don’t have one already), and also run the DualOptiboot bootloader for this to work. Moteinos come with this bootloader (all orders since the other Wireless Programming post and code was released). If you have all these components right, any Arduino clone with an RFM12B transceiver and an SPI Flash chip of at least 32Kbytes of memory will do the job.
Just for fun, here’s how the end of a wireless upload looks like, notice there were 617 packets sent all the way from the PC (through the python script) to the attached Moteino (gateway), wirelessly to the remote Moteino (target node):
