Update: LTO is enabled by default for avr core/board version 1.6.12 and newer.

@scalz - You're right. There doesn't seem to be an issue with mouser. I must have gotten hooked up with digikey and some of the smaller sellers. I have a contact ticket open with mouser and the manufacturer for one of the models, as they can't tell me what the code means and the datasheet doesn't specify it either. Will post back here with what the order code "988-AT25DF512CSSHNGU-B" means. The minimum order is £33 for me at the moment, I seem to remember this being a little higher last time i checked, so not sure if its a limited time thing (worth a look if anyone wants anything from there). Is anyone in need of these ICs as i would order some for you and post to you if you just cover the cost of the item and then the postage for them (more than likely cheaper than paying for postage from them at £12 per shipment, to the UK anyway).

BTW, I like how you both made a case for it. Very nice!

@koresh said in Button size radionode with sensors swarm extension: @christoph-blank Hi, thanks for using this board. In the first version of this board the divider is conected after LDO, so you can't measure voltage above 3.3V. In the second version the divider is connected to the battery directly. You use 3.2v battery so it is not problem for you. But LiFePo4 battery has very flat discharge curve so it can be hard to read this level with reasonable accuracy. I will try to find LiFePo4 battery and add some piece of code soon. Yet you can play with followed code // Get the battery Voltage int sensorValue = analogRead(BATTERY_SENSE_PIN); // 1M, 470K divider across battery and using internal ADC ref of 1.1V1 // ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts /* The MySensors Lib uses internal ADC ref of 1.1V which means analogRead of the pin connected to 470kOhms Battery Devider reaches * 1023 when voltage on the divider is around 3.44 Volts. 2.5 volts is equal to 750. 2 volts is equal to 600. * RFM 69 CW works stable up to 2 volts. Assume 2.5 V is 0% and 1023 is 100% battery charge * RFM 69 HCW works stable up to 2.5 volts (sometimes it can work up to 2.0V). Assume 2.5 V is 0% and 1023 is 100% battery charge * 3.3V ~ 1023 * 3.0V ~ 900 * 2.5V ~ 750 * 2.0V ~ 600 */ #ifdef MY_IS_RFM69HW int batteryPcnt = (sensorValue - 750) / 1.5; #else int batteryPcnt = (sensorValue - 600) / 3; #endif Thank you very much, what are the other differences between V1 and V2? I believe I have V1 but I'm not sure. The above code is what I currently use, and I removed the sensor part of the module. However, it shows 100% until the end (until it's not sending anymore). Looking forward to your tests! Christoph

@MiKa which box are you referring to? Generic boxes are available here: https://www.mysensors.org/store/boxes

@fets So far, I have only built the 5x5 board (but the others should be schematically identical). The only issue I have found so far is that I cannot get the ISP port to work. But I have checked and I have an identical setup on the 1.0 board and that worked, so I suspect the programmer is too weak to drive the net on this one. So it is not a board-issue per se, and might only be an issue on the 5x5 board as routing is the most complex on that one due to the size.

@djbonet you’re welcome. If I remember correctly, the datasheet diagram shows the limit for 8MHz to be 2.4V