PICAXE-08M Sequencer
My 2m station includes a masthead preamp, a 600w linear and the IC-910. In order not to blow up the preamp I needed to get a sequencer, me being me I decided to design and build one, total cost with the box was around £10. This is a very simple design and uses a PICAXE-08M for the control as it supports 5 input/outputs. All I needed was 1 input (PTT) and 3 outputs, preamp, TX Amp and radio. The preamp, TX Amp and radio outputs are driven by a relay so can be configured for NO or NC in hardware or this can be done in software too. The delay on TX is 100ms between the preamp going off and the TX amp coming on and then a further 50ms for the radio to move into TX. On un-keying the radio is moved into RX, 50ms later the TX amp is removed then 100ms later the preamp comes back on. There are 4 LEDs, a green one for power, one red/green for TX/RX, a green one to indicate preamp on/off and a red one for indicating the TX has come on.
Updated to v1.2
I also cleaned the code up, adding comments and symbols, to allow whoever builds it to customise the outputs in and better understand the code if they are new to PICAXE.
NOTE: If this design is to be used with a radio which goes into transmit when the PTT line is grounded then you can omit D3 and REL3 and connect the PTT line of the radio directly to the collector of Q3.
Downloads
v1.2
| ExpressPCB Schematic and PCB layout v1.2 (ZIP) |
| Schematic Layout v1.2 (BMP) |
| PICAXE Code v1.2 (BAS) |
v1.0
| ExpressPCB Schematic and PCB layout v1.0 (ZIP) |
| Schematic Layout v1.0 (BMP) |
| PICAXE Code v1.0 (BAS) |