Ondrej Bajer

Hi guys, so I bought a handbag of components, and tried to put everything together. Result is not that bad - it works at least And when compared to RGBW, it's a HUGE improvement, also. I'm reading a value from Analog Input #3 (10bit, 0-1023) every 5140ms. Then I report it back as °C. HC2 is set to 10s polling For example, an absolute value of 348 is transaled into 38,4°C, maximum value of 1023 will be reported as 102,3°C - which is nice. As you can see on the chart, there's a lot of noise visible, but now it's okay for me. The chart shows a fluid level lowering, as I started pump to test the sensor. 1) For me, slow reading is not an issue, but for other applications this might be a problem. Especially if one wants to collect more samples over a short period of time and then calculate an average to eliminate spikes. Clearly, this ADC implementation is not meant for audio recording, of course. 2) I found the same issue. Even if I pull-down A0-A2 with resistors, there's a leakage between inputs. A0-A02 inputs are giving very similar values to the A3, where I have external voltage applied. I tried to put 1s delay before reading each input, but that didn't help either. (Now I wonder what would happen, if I read A3, then read A0, wait 1s and read A0 again...for a shame I cannot test it today...) Anyway, it looks like a viable solution, so I will try to experiment with different pull-downs and capactitors for low-passes. Just to see, whether I'm practically limited to a single Analog Input per Z-Uno board, or not. Low impedance input buffer would be a sure solution, but I'd like to avoid of using more IC's, as much as possible. One thing to add: My watter-pressure sensor gives 10V for 6 meters of watter level. Height of my tank to the very top is 2,7m. That means that the maximal voltage I will ever get from the sensor is 4,5V. Since Analog Input pins of Z-Uno are operating in range 0-3,3V, I have to lower the input voltage to be safe. For the start, I simply divided voltage by 2, using resistor divider. To use the full scale, and still be safe, it would be better to divide by 1,5 (4,5 / 1.5 = 3V). So, is it a good idea to use 10K+20K resistors for this? Plus a small capacitor as a low-pass?

I need to continuously measure the fluid level in my nuclear waste tanks, so I have a pair of LMK307 fluid-pressure sensors already submerged in. Datasheet attached. I went for analog, 3-wire, 0-10V version, as other options were RS485 or HART protocol, which seemed too complicated to be read by any mass-production z-wave device. What a mistake! If I knew, that RGBW module's resolution is so poor and even needs a buffer circuit, I would choose RS485 + some z-wave DYI board instead. Now, I have to use a DIY (Z-Uno) anyway. By the way, are you aware of liquid-pressure sensor, that emulates DS18B20, aka Dallas digital temperature sensor? As 1-wire input for Dallas is on almost every Z-Wave micromodule...door/window sensor, motion sensor, DIN Rail modules etc. To be honest, I will not throw away my pressure sensors, but Dallas emulation could be a solution for other people looking to solve the similar task. LMK307_SONDA keramika LMK 307 0-6mH2O 0,6bar 0-10V PVC kabel.pdf

Based on what I did to the poor CA3140E depicted below, I would say that you are much better than me Anyway, one piece of Z-Uno is on the way to my residence. I'll try not to kill him too early.

So, how about to produce just a PCB with a power and input circuits and a socket for holding Z-Uno. PCB will be equipped with terminals, that can be screwed on to pins from the photo (Haseman DIN rail casing for Fibaro RGBW). For the start, let just use standard 12-bit ADC resolution, 0-1023 (which is 10x finer that RGBW module's capability). Still not interested? Thanks, Ondrej

Hi Tinman, My sensors have accuracy of 0.5% F.S., so getting somewhere closer to this would be nice. I'm looking for 12 bit ADC, which is 4095 counts. 4095 counts on 0-10V scale, translates into step size 0,0024V This should be achievable using Z-Uno plus two circuits, I hope: - The input circuit to adapt 10V to Z-Uno's analog input. - Power stabiliser, to adapt 24V power source to Z-Uno's needs. Are you interested, please? PS: I would say that many people will be interested in buying such device over time, as 0-10V is defacto standard. Yes, Fibaro RGBW module can be adapted, using a buffer circuit from @petergebruers , but RGBW module itself has very poor resolution: 0-10V with a 0.1V step size. That's just 100 individual levels. Simply the ADC in RGBW is meant to be controlled by dimmer/potentiometer, so 100 levels is OK. But for long-term measurement it's not a realiable solution, as I learned.

Hi guys, I need a Z-Wave analog sensor, that is more precise (and more stable) than a RGBW module. Since my technical skills are very limited, I'm offering a deal to anyone who is interested in building such device for me. Requirements: - have to work with HC2, EU frequency - 4 analog inputs 0-10V - resolution 12 bit (4096 individual levels) or better - reports value on POLL or Level Change - device reports itself to HC2 as a temperature sensor, 0V=0°C, 10V=100°C - have to work with industrial 0-10V sensors, Rmin=1MOhm (IE: industrial watter level pressure sensor) - powered by 24V power source - no batteries needed for operation - DIN rail casing I'm offering 250EUR for a working device. Anyone interested, please let me know. Background story: I need to continuously monitor watter level in 3 separate tanks with HC2. I've tried to use RGBW analog input, but watter level was chaning very slowly (cca 0.1V per 14 days) so that RGBW was not able to notice that change. Translation into temperature is needed because temperature is one of the two variables that HC2 is able to visualize using weekly chart (the other is power consumption). Thanks beforehand, Ondrej Bajer

Hi Peter, works great! Thanks a lot for sharing your knowledge. ONDREJ