- Complete the assembly of the new Probe (viewtopic.php?f=15&t=111). This consists mainly of sealing the tube and adding the float.
- Complete the assembly and testing of the B-Model Interfacing (viewtopic.php?f=15&t=113). Most of the wiring is now complete and the integration of the Mk2 Probe with standalone software is complete. With the addition of four more wires and two buffer ICs it will be possible to test the rest of the Interface.
- Integrate the completed Interfacing and Probe into the Software Framework. This has been started, but there is a reasonable amount of coding and a fair bit of testing to do, including in a system with a ButtsPi.
- Sort out the power supply for ButtsPi. This is currently performed using PoE from SumpPi, but the new B-Model Interfacing has dropped that. We could still inject the supply at the Sump end, but that may well require two PSUs in that location (12 V and 19 V). The other approach is to recycle the existing 19 V PSU from SumpPi to Butts Pi and connect it directly.
- Final integration on site.
Integrating the New SumpPi Interface into the System
Integrating the New SumpPi Interface into the System
This Topic is to cover the activities to be carried out to allow the current SumpPi installation to be upgraded to use the new Magnetic Level Probe Mk2. As they are completed, or new tasks identified, they will be recorded here. At this point, the following has yet to be completed:
Terry
Re: Integrating the New SumpPi Interface into the System
That looks a good plan.
It will take the best part of a week (given other activity) to build another probe or two, work will be underway this weekend.
I have a sealing solution, which I need to trial, for the bottom end of the probe and a design for the top end that needs for be printed. A new float design is now ready to go but in the meantime we can use the existing ones.
When do you want a sealed, ready to go, probe available for integration?
It will take the best part of a week (given other activity) to build another probe or two, work will be underway this weekend.
I have a sealing solution, which I need to trial, for the bottom end of the probe and a design for the top end that needs for be printed. A new float design is now ready to go but in the meantime we can use the existing ones.
When do you want a sealed, ready to go, probe available for integration?
Re: Integrating the New SumpPi Interface into the System
Penri,
I was aiming for Tuesday and I've fully assembled the Interfacing and have been debugging and testing the Level shifters. Unfortunately, I've just realised that I made a naive design assumption about the 4050 hex buffers; they can only translate levels from high to low and not the other way round. I've had a search for a suitable 16-pin DIP replacement, but they do not seem to have the current capability we need.
So I can either go back to the NPN/PNP transistor pair design in the prototype or if you are aware of a suitable alternative, I'll design around that. I have the components to put together two NPN/PNP transistor pairs, but the Veroboard will have to be hacked a bit to make them fit.
Any ideas?
I was aiming for Tuesday and I've fully assembled the Interfacing and have been debugging and testing the Level shifters. Unfortunately, I've just realised that I made a naive design assumption about the 4050 hex buffers; they can only translate levels from high to low and not the other way round. I've had a search for a suitable 16-pin DIP replacement, but they do not seem to have the current capability we need.
So I can either go back to the NPN/PNP transistor pair design in the prototype or if you are aware of a suitable alternative, I'll design around that. I have the components to put together two NPN/PNP transistor pairs, but the Veroboard will have to be hacked a bit to make them fit.
Any ideas?
Terry
Re: Integrating the New SumpPi Interface into the System
Terry
Apologies for delay in replying I was out yesterday late afternoon / evening.
I think what you need is an open collector or open drain buffer, like the SN7407 or SN74LVC07A, they may need a pull up resistor to the "high" voltage Vcc, dependent on what they are driving.
Hwyl
Penri
Apologies for delay in replying I was out yesterday late afternoon / evening.
I think what you need is an open collector or open drain buffer, like the SN7407 or SN74LVC07A, they may need a pull up resistor to the "high" voltage Vcc, dependent on what they are driving.
Hwyl
Penri
Re: Integrating the New SumpPi Interface into the System
Penri,
In case you had already looked at mey last post. I've deleted it because I was answering the wrong question.
I'll look into your suggestions. CPC do the SN7407 for 60p each, but I may have some.
In case you had already looked at mey last post. I've deleted it because I was answering the wrong question.
I'll look into your suggestions. CPC do the SN7407 for 60p each, but I may have some.
Terry
Re: Integrating the New SumpPi Interface into the System
Terry,
As you may have guessed, or know, the SN7407 is a TTL device, I didn't check whether the RPi can drive the input voltage switching it needs.
Hwyl
Penri
As you may have guessed, or know, the SN7407 is a TTL device, I didn't check whether the RPi can drive the input voltage switching it needs.
Hwyl
Penri
Re: Integrating the New SumpPi Interface into the System
Penri,
I'm just looking at that. It is also a 14-pin DIL instead of a 16-pin, so although the existing sockets could be used, it's not ideal.
I'll let you know what I find.
I'm just looking at that. It is also a 14-pin DIL instead of a 16-pin, so although the existing sockets could be used, it's not ideal.
I'll let you know what I find.
Terry
Re: Integrating the New SumpPi Interface into the System
Terry
I have a SNJ5407 and DM 7406 (it's inverting cousin), both TTL and 14 pin.
Hwyl
Penri
I have a SNJ5407 and DM 7406 (it's inverting cousin), both TTL and 14 pin.
Hwyl
Penri
Re: Integrating the New SumpPi Interface into the System
OK. However, I've literally just finished ordering enough to do all of the Pis and have a few spares. I also ordered a set of 14-pin DIL Sockets to go with them. The sockets will be here tomorrow, so I can complete the new Veroboard layout and the chips should arrive on Monday or Tuesday.
Are you sure that the device that you have is a SNJ5407? I can't find that online. What I've ordered from CPC is SN7407N, which is DIL packaged.
The device will work with a Pi because the Pi Hi-Level output is 3.3 V and the minimum Hi-Level input of the SN7407N is 2 V.
I'll get on with redesigning the circuit.
Are you sure that the device that you have is a SNJ5407? I can't find that online. What I've ordered from CPC is SN7407N, which is DIL packaged.
The device will work with a Pi because the Pi Hi-Level output is 3.3 V and the minimum Hi-Level input of the SN7407N is 2 V.
I'll get on with redesigning the circuit.
Terry
Re: Integrating the New SumpPi Interface into the System
Terry
It's a SNJ5407J, a mil. spec. ceramic packaged version of the 7407. It's probably been in my possession for the best part of 40 years.
Hwyl
Penri
It's a SNJ5407J, a mil. spec. ceramic packaged version of the 7407. It's probably been in my possession for the best part of 40 years.
Hwyl
Penri