HiRel/CanSat/Slave Power

From FSI
Jump to: navigation, search


This board powers the CanSat system either from a battery or from an USB connector.

CanSat Slave Power Schematic Description
CanSat Slave Power V1.0 CanSat Slave Power v2.0 Schematic PDF LDO 5V -> 3V3:
v2: AP7361-FGE-7

It additionally provides a serial port over USB, 4 switches and 2 LEDs.

Power inputs

The CanSat system has 3 possible power sources:

  • a micro-USB connector on the power supply board
  • a battery connector on the power supply board
  • a micro-USB connector on the microprocessor board

Only one of these should power the system with 5 V. Jumpers are provided in order to select the actual power source. This 5 V is distributed to all the boards on the top connector disk.


The power board generates 3.3 V from 5 V. The 3.3 V is distributed to all the boards on the bottom connector disk.

Power usage

The 5 V is used by:

  • the power supply board for generating the 3.3 V
  • the sensors board for the Max11300 together with the temperature and pressure sensors

The precision of the 5 V is given by the components' requirements:

  • the DC/DC converter needs 2.9 V ÷ 5.5 V
  • the Max11300 mixed-mode I/O interface needs 4.75 V ÷ 5.25 V
  • the pressure sensor needs 4.75 V ÷ 5.25 V
  • the temperature sensor needs 2.5 V ÷ 5.5 V

The 3.3 V is used by:

Board connectors

Additionally to the Power supply, the power board provides:

  • 4 switches
  • 2 LEDs
  • a serial port

The connection to the module is done through following pins:

XBee I/O connections
name pin dir description
TxD b1 out serial link TxD
RxD b3 in serial link RxD
Led_0 b5 in user LED 0
Led_1 b7 in user LED 1
switch_0 b2 out DIL switch 0
switch_1 b4 out DIL switch 1
switch_2 b6 out DIL switch 2
switch_3 b8 out DIL switch 3


Device DigiKey Part No Description Quantity
10104111-0001LF 609-4053-1-ND GDH04S04 SWITCH DIP HALF PITCH 4POS 24V 1
1571983-5 450-1762-1-ND FTDI IC USB FS SERIAL UART 28-SSOP 1
AP7361-FGE-7 AP7361-FGE-7DICT-ND DC-DC 5->3.3 ADJ 1
GRM21BR60J106ME19L CAP CER 10uF 6.3V 20% X5R 0805 1
08056D475KAT2A 478-1416-1-ND CAP 4.7uF 10% X5R 0805 1
Resistance 0603 75k 1
Resistance 0603 24k 1
Resistance 0603 100 5
LED 0603 green 2V2 15mA 5
GDS04S04 / 1825006-8 450-2162-ND SWITCH DIP SLIDE 4POS SMD 1
Personal tools
Modules / Projects