PSAS/ news/ 2004-05-30 - Critical path scheduling and APS

8:00am - 11:00am at ?Andrew's "cabin"


  1. Prioritization and schedule of our critical path stuff: APS, GPS, Magnetometer, etc.
  2. Prototype APS (Avionics Power Systems) battery selection, architecture and design handoff to Ted and Ivan.
  3. GPS stuff.


What we decided to do: keep the APS just as it is now (a glorified power switch with some power monitoring) and have Ted and Ivan develop an independent battery charging circuit with a charging IC.

We decided on a 4 cell pack: however, this means that we need a power switch on the WiFi and on the ATV power amp. Probably just a comparator and an IPS with a NAND gate that doesn't let the PIC turn on the amplifiers if the bus voltage is > 15V (or whatever their V limits are). See data sheets, but: ATV power amp has 16V max input, WiFi power amp has a 15V? limit).

The IC that charges the battery packs: one per pack:


Nice things:

To Do:

TR 1. Get Andrew the graphs for the Kodak batteries if possible.


Ok schedule:

2004/06/01 Research
2004/06/15 Schematic
2004/07/01 PCB Design
2004/07/15 PCB's soldered up (hardware done)
2004/08/01 Firmware
2004/09/01 Freeze
2004/09/20 Launch

Reduce Andrew's bloodpressure's timeline:

2004/06/01 Research
2004/06/07 Schematic
2004/06/21 PCB Design
2004/07/07 PCB's soldered up (hardware done)
2004/07/14 Firmware
2004/09/01 Freeze
2004/09/20 Launch