Category: Electronics

  • Crossbow LRS, hardware

    Weather outside is bitchy. Period. It rains, then it's windy and then maybe there is some direct sunlight for 15 minutes. No way to fly or test my DIY RC radio link. But, there is some progress after all. My latest changes seems to be working just fine. On a bench link was stable for…

  • Hands on: LoRa32u4 II 868MHz LoRa development board

    Idea for Crossbow, DIY LRS system did not appearned in my mind out of nowhere. All my previous LoRa attempts were aimed at telemetry purposes only. E45-TTL-100 are cool, but bulky. If I would want to use them, I would either have to attach Arduino to it or hack it open and reprogram onboard CPU…

  • E45-TTL-100 not transmitting when connected to Arduino

    While working on one of my project involving Arduino and E45-TTL-100 LoRa 868MHz radio modules, I’ve discovered that it is not working exactly like expected. Documentation states: (…) When the data inputted by user is up to 58 byte, the module will start wireless transmission (…)(…) When the required transmission bytes is less than 58…

  • Testing 868MHz LoRa range, part 3: round trip

    After determining that range of 868MHz LoRa wireless modules E45-TTL-100 have, at least, quite impressive range (5,7km and I was out of line-of-sight to test further) I’ve decided to test something else. In the beginning I was planning to use those radio modules for telemetry only, but then another thought crossed my mind: why not…

  • Quick note on SEMTECH SX1276 100mW output mode

    Few facts about SEMTECH SX1276 LoRa modem and 20dBm (100mW) mode: +20dBm (100mW) is possible only on PA_BOOST pin Pins RFO_LF and RFO_HF allows only up to +17dBm (50mW) Maximum allowed duty cycle while using +20dBm mode is 1% Maximum allowed VSWR while using +20dBm mode is 3:1 The biggest problem with +20dBm on PA_BOOST…

  • Hands on: Tiny Frsky 8CH Receiver from Banggood

    I have a nasty habit of buying things and then forgetting about them. Something like that happened to Tiny Frsky 8CH Receiver (Wolfbox F802 software compatible) from Banggood I’ve purchased last year. For some time I used it in JJPro P175 quadcopter, but then it landed in a box and I forgot about until last…

  • Testing 868MHz LoRa range, part 2: open space

    It was a good weekend. At least for me and CDEbyte E45-TTL-100 868MHz LoRa serial wireless modules based on SX1276. Why? Since weather was nice and looks like those modules are way better than datasheet specifies. Specs states: 3km in open space. And I’ve proven almost twice that much range! Last Friday I’ve placed one…

  • Testing 868MHz LoRa range, part 1: urban area

    With a (more less) free evening I decided to finally start testing range of 868MHz LoRa E45-TTL-100 radio modules I described only yesterday. Instead of building new testing rig, I only upgraded testing setup I used to test range of FS1000A and XY-MK-5V 433MHz radio modules. Few hours later I came up with this: I’ve…

  • E45-TTL-100 868MHz LoRa wireless modules

    E45-TTL-100 868MHz LoRa wireless modules

    My quest for ultimate (?) DIY telemetry system for UAVs continues. Last year I was playing with HC-12 433MHz wireless modules with pretty decent results. After all, more than 1km of range for a few bucks is more than acceptable. Still, HC-12 has at least few problems: