BoSL Board v0.4
Contents
This site provides a list of all the future improvements we would like to make for our BoSL baord. Let's separate this into immediate and future plans
Immediate Plans for our Next BoSL Board v0.4
1. Real Time Clock module [Done]
2. GPS antenna [Done]
3a. Battery connection moved to ensure that the plug sits over components and not hanging outside the board [Done]
3b. Ethernet connection moved to also ensure that the plug sits over the components instead of hanging outside the board (e.g. we could just turn it around by 180degrees) [Done]
4. Pin 2 & Pin 3: we will free these 2 pins for attachinterrupt by changing the current softwareserial to other available digital pins [Done]
5. Atmega chip - change to the smaller one which we used for sensors [Done]
6. Smaller screw terminals - still black in colour, but smaller footprint. [Done]
7. Passive antenna options for comms [Done]
Below are visualizations of the BoSL rev 0.4
Board Bottom
Board Top
Long term plans for our future BoSL boards
1. RS485 connector
2. ATmega chip change to ATmega 2560 which is the one being used on Arduino Mega --> this will give us more digital pins especially more pins for attach interrupt
3. Two versions - one version will be without having the pressure sensor on it
7th May 2020
Some reading and investigation was done into what type of connector would be best for the RS-485 BoSL Sensor Interface.
The 6P6C connector was found to be the most suited for our application as it is:
- readily available and so inexpensive and unlike to have supply issues
- easy to terminate cable to with a crimping tool
- smaller than the current 8P8C connector, allowing more ports in a smaller envelope
- easy to insert and remove with locking feature to not be accidentally disconnected
As there are only 6 contacts, 3 pair twisted pair cable may be used, however 4 pair is still viable if need be.
The 6 connectors will be designated as follows:
1. GND
2. 3.3V
3. RS485 D+
4. RS485 D-
5. WAKE
6. Reserved
Without the WAKE line it would be possible to move down to a 4P4C connector however adding the WAKE line gives much more flexibility with regards to power saving options. Without it all the sensors attached would have to be woken simultaneously, making power management much more challenging.
The next revision of the BoSL board is going to switch micro controllers, from the ATmega328p to the SAMD21. The SAMD21 is a much more capable Arduino compatible micro-controller, with up to 32 KB of memory, preventing future bottlenecks associated with the more limited capability of the ATmega328p. The SAMD21 also has many useful integrated peripherals of an RTC, and a USB controller, hence these distinct components on the current BoSL board will be able to be removed.
