Sunday, November 11, 2012

Progress! Radio Popper and LP160 are talking!

After months of tinkering, taking voltage readings to figure out which cables went to ground and other fun stuff, I've got the Lumopro LP160 flash unit talking with the Radio Popper JRX Studio receiver.

The original goal was to directly control the IGBT circuit so that the SYNC / QUENCH pin functionality would work with the Radio Popper(s). However, this proved to be a real pain in the rear end. For one thing, there isn't much room for cables to be routed. For another, dealing with the IGBT means dealing with dual voltages, and I just want to do fairly straight up wiring and control.

Bypassing the LP160's builtin controller also means losing or having to re-implement much of the functionality of the LP160 itself. In which case... I was better off building my own flash from scratch.

So, after some tinkering and reworking my original idea, I have basically gotten the Radio Popper JRX receiver to talk to the LP160. What follows is a brief video showing me operating the LP160 through the Radio Popper JRX transmitter:




What is shown in the video:

  • LP160's display panel indicating current power levels and zoom levels.
  • LP160's flash is working.
  • With the Radio Popper JRX transmitter dial being turned, the power level on the LP160 likewise is updated. The update occurs through the LP160's power toggle, so when the power level needs to be higher than where it is at, the power level setting toggles past the end and wraps around.
  • SYNC from the transmitter works through the setup.
  • With the Radio Popper power level setting set to near minimum, I have configured my interface to allow the toggle'ing of the LP160's zoom setting.
Some bugs that made it into this version of my hardware/software:
  • Accidentally set the limit for the power level at 1/32 power, when the LP160 can go to 1/64 power.
  • Occasionally, the power toggle will skip, resulting in extra rounds toggling.
The todo(s) still remaining:
  • Getting everything to fit neatly inside of the LP160. 
  • Making sure that my solder points/etc. are clean and durable.
  • Create the pinouts to allow me to reprogram the circuit without having to take apart the LP160 again... which, btw, is a major pain. :(
Anyways, that's the update thus far. Since the Radio Popper JRX has 3 groups of power, this basically allows me to control multiple flashes' power levels, even if they don't support quench pins! This mod also allows me to change the gearing of the Radio Popper's dial. Ie, with the right calibration, I can set different functions for different power dial settings. 

The goal is to get it so that I don't need to manually change the power on my manual hot shoe flashes. With this mod, I can add the interface functionality for a few dollars per flash unit, in parts. Though I need to figure out an easier way to get into the innards of the flash unit... as it stands, the LP160 requires you to disassemble the flash head assembly before you can open the main body of the flash. 

Side note:
  • The times when I hit the SYNC button and nothing happens, there is apparently a delay built into the Radio Poppers, where the SYNC test button can't be hit more than once every half a second or so. However, tests on-camera, validates that the sync works normally when not using the SYNC test button.