Sensorberg Interviewer Embedded Test

Hey Interviewer! This is our repository for a little test to validate your way of working, thinking and problem solving. You will find a bunch of questions below which you can answer. Lets start:

1. Schematics and Datasheets

Look at the schematic in this repo and answer the following questions. You might need to read a bit in the datasheet of the components. Everything you will need for this exercise can be found in this repo.

1.1 Which GPIOs do you need to drive HIGH to get the color Pink on the RGB LEDs (D1,D2,D3)?

1.2 Which interface is used to communicate with the GPIO-Expander MCP23017 and what is the Address (in hex) to reach it?

1.3 Under which conditions will LED D4 light up?

1.4 It turns out that touching the PCB somehow makes the LED D4 light up and flicker, why could that be?

2. Software

Look at the 'main.py' file and answer the following questions

2.1 Please describe what the code together with the schematic is doing.

2.2 What could make this code better? What would you change?

2.3 From the schematics there are 2 GPIOs used for the OR-Gate C1. Which GPIOs are used and how do you need to initialize them correctly so the LED D4 is turned off? (ignoring the fact that the OR-Gate C2 could turn it on).

3. Concept

You can find a WiKi page containing a User-Story as a task please find it and complete the task.

To answer the questions you can send an E-Mail. There is no need to interact with this repository.