Difference between revisions of "RS-485"
(Created page with "Here we will log the development of RS-485 interface onto BoSL sensors. Requirements: * Upload Code * Sleep/Wake sensors * 3V3 5V interoperable * Minimum wires * Bus operation") |
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* Minimum wires | * Minimum wires | ||
* Bus operation | * Bus operation | ||
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| + | Uploading code is the first issue to be addressed. RS-485 is half-duplex over a single twisted pair. This presents issues during uploading as it requires full duplex operation. | ||
| + | The easiest solution is to move to full duplex. This would require 2 twisted pairs thus a full bus likely 8. Ideally less wires would be needed. <br> | ||
| + | Another solution is to modify the uploading program and use another wire to send to the sensor whether it should be receiving or sending data. This would likely require special programmer hardware and software. <br> | ||
| + | It is also possible to update the Arduino bootload to recognise when it needs to be sending and receiving data. This may be possible, but it is uncertain how reliably this would work or if it is feasible. <br> | ||
| + | Additional wires could also be left exposed on the sensors so that uploading remains possible via these. This solution is is difficult as it introduces another entry point for water. <br> | ||
Revision as of 07:31, 6 July 2020
Here we will log the development of RS-485 interface onto BoSL sensors.
Requirements:
- Upload Code
- Sleep/Wake sensors
- 3V3 5V interoperable
- Minimum wires
- Bus operation
Uploading code is the first issue to be addressed. RS-485 is half-duplex over a single twisted pair. This presents issues during uploading as it requires full duplex operation.
The easiest solution is to move to full duplex. This would require 2 twisted pairs thus a full bus likely 8. Ideally less wires would be needed.
Another solution is to modify the uploading program and use another wire to send to the sensor whether it should be receiving or sending data. This would likely require special programmer hardware and software.
It is also possible to update the Arduino bootload to recognise when it needs to be sending and receiving data. This may be possible, but it is uncertain how reliably this would work or if it is feasible.
Additional wires could also be left exposed on the sensors so that uploading remains possible via these. This solution is is difficult as it introduces another entry point for water.
