Side Panel Interface
From endrobene wiki :: ITE
Side Panel Interface is an electronic µC-based board that grants primitive user interaction with robot. Here is a full list of user interface devices it provides:
- Infrared receiver (36 KHz bandwidth) (receives infrared signal from remote control devices, such as typical multimedia RC)
- Power-on button
- Three LEDs to indicate current working state
- Charger socket (2.5mm)
This board is mounted on the side of the rear section.
Contents |
Functions
- Indicate Charger_connected (Red LED)
- Indicate Charged_state (Red blinking LED)
- Indicate System_standby (Blue blinking LED)
- Indicate System_Running (Green LED)
- Limit turn-on/off frequency (user will not be able to turn-off and on device faster than once per 5 seconds)
- React on infrared signal and infrared sequences
- React on button sequences (power up, power down, etc)
- Output Power_enabled, Reset signals
Schematic capture
Important interface notes:
| Port | Direction | Function |
|---|---|---|
| XP6 | In [CMOS5] | XINPUT1 - Battery Charge has Finished. Reported by PPC. This signal will be triggered not when the battery is charged, but when user shall think that the battery is in charged state. PPC sees more details in hardware level, so e.g. if one battery block is damaged, the signal will be toggled HIGH when 100% of good batteries are charged to satisfactory charged level (might be less than 100%). |
| XP7 | Out [CMOS5] | XOUTPUT1 - Enable PPC operation. Reports to PPC that the user has intentionally submitted a command to have entire system in either Enabled or Disabled state. The PPC will decide to which power state the system should switch from current state. SPI hides random clicks on the button or unsolicited infrared commands by providing clear target system state. Implemented this way because SPI is operating at HMI level and should understand user intentions better, then the close-to-hardware components. |
| XP8 | Out [CMOS5] | XOUTPUT2 - Charger Power is Good. Reports to PPC that charger is connected to the PPC and the charger power supply level is sufficient and stable for some time (few seconds). This is done to prevent random blinking and jitter duing attaching and detaching of a power cable, and to prevent charging from a weak or wild power supply. |
| XP5 | Inout [5V Open Drain] | I2C interface. Usage could be debuging and message-passing. |
PCB Layout
Device photo
Test results
Test results were positive when device was running on high-power 5V rail. It was put to +5Vsb with low current output from PSU but with high self current consumption which caused thermal shutdown (!) of standby +5Vsb source chip. Due to this, resistors on LEDs have been increased to 510 and 750 Ohms.
Recommendations
What shall be fixed in next version:
- 1) Enhance D1 (Add mounting diode places in parallel, more powerful diodes in SMC);
- 2) Reduce LED power consumption (increase LED resistors to values above 510 and 750 Ohms - charging and operating mode);
- 3) Split LED power (operating and others) with standby input voltage;
- 4) Move Reset switch away from another input. Move aside inputs from outputs. Put text labels on Output_Reset and Output_On, and also Input_Charged
Specifications
- Stand-by power consumption table:
| Part name | Standby current, mA | Standby power, mW |
|---|---|---|
| TSSOP1736 | 1..5 | 5..25 |
| Green LED+Logic | 4 | 20 |
| Blue LED+Logic | 4 | 20 |
| Red LED+Logic | 5 | 20 |
| MCU Active mode | >6 @ 8MHz (>3 @ 4MHz) | >30 (>15) |
