After trying and documenting the Brotronics Broversity RX, I tried out a Brotronics PowerTower Rx. While the github page has schematics, sadly it does not even include a clear labelling of each pin, or the fact that output 5 seems not to be wired to a pin at all.
You would buy the PowerTower Rx because you want a lipo backed up receiver which will sound an alarm on a loud buzzer (that you provide) once the signal is lost. It will also switch to transmitting a distress find me beacon after signal has been lost for 45 seconds, so you can use the radio signal to go find it, even if your main battery has been ripped out after a crash (happened in all my crashes).
For more details on how that works, see my post on Brotronics Broversity RX, the missing manual.
This receiver is more compact, cheaper, but does not have diversity RX, which is likely ok for most uses. But as I mentioned, it comes with 0 documentation, and not even a proper pin mapping. I ended up documenting this in this rcgroups post, but I thought I should make a proper page here with that info:
There are 8 outputs in the RX configurator, but I believe only 7 are wired (#5 seems to be going nowhere?)
If you use the buzzer for loss signal and loss model finder (you should) and don't solder to use RX/TX, you're really only left with 3 servo ports since #1 is used for PPM to your flight controller
Port 2 can be connected to directly and 3 and 4 (RSSI and SCL) need to have a custom cable made because the layout did not include enough pins to just replicate Gnd/Vcc in the right places.
Here are the channel outputs you can configure in the RX tab of the openlrsng configurator:
The labelling on the board is pretty poor though. Here are the pins:
Pin1: PPM (port #1)
Pin2: Vcc (+ on the board is not aligned with it)
Pin3: Gnd (not labelled at all)
Pin4: Gnd (labelled -, off center a bit)
Pin5: RSSI (port #2)
Pin6: lbeep (I believe it's also port #2 and activated by a soldered jumper)
On the other side of the board, you have:
Pin1: Buzzer -
Pin2: Buzzer + => connect a buzzer to those 2 pins and set output port #6 to 'link loss'
Pin3: SCL is port #4, but you'll have to write your own servo cable with GND and VCC from other pins
Pin6: SDA => this allows to plug a servo cable between pins 4,5,6 to get Output Port #2
The wiring does allow to plug a servo cable directly into PPM on one side and Gnd/5V/SDA on the other side.
- labelled SDA, can be analog
- labelled RSSI on board, can be sending different signal to lbeep pin if you solder a jumper
- labelled SCL, can be analog
- may not be wired anywhere
- link loss indicator (buzzer port, labelled BZ+ BZ-)
This means you can connect to port #1 and port #2 directly with a servo cable.
Port #3 require that you route your own wires to make a servo cable out of pin 5 inthe back, Vcc and Gnd
Port #4 is the same with SCL, you have to make your own cable and route Vcc and Gnd
Port #5 does not seem to exist on the pins I could find
Port #6 is nicely wired with Bz- and Bz+, you just connect a 2 pin powered buzzer there
Ports 7-8 for RX/TX are on the other side of the board, you have to solder on them for some reason.
The battery port is also missing a header, but at least it has holes to add one. To be honest, I have no idea why anyone would buy this receiver if you're not going to use the battery backup. There are otherwise some cheaper or better wired ones you can buy (I did buy it for the battery backup which I think is a fantastic idea)