Homini Complete Room Sensor Module?
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I would like to separate the 3v3 to the MCU and the radio from the rest of the components, this way i can safely power the MCU and Radio with the programmer when uploading software with just the programmer attached. But i want it so if it is powered externally i would like the board to use that power.
I'm proposing the use of diode(s) on the power lines in between the MCU and radio to stop the flow going out to the rest of the circuit. I'm hoping that by using the diode(s) to stop the 3v3 from the programming feeding to the whole 3v3 circuit it will not draw enough current to damage the programmer and the PC. By using this diode i believe that the MCU and Radio will draw the strongest voltage of whatever is connected, if nothing is connected other than the FTDI or ISP programmer then it will only power on the MCU and Radio. A quick hand drawn sketch below:
Do you feel i'm going about this the correct way rather than separating the MCU and radio with a hardware jumper? One less thing to care about while programming in my opinion.
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And the prototyping begins! Pretty much all of the breadboard versions of parts have arrived and i will be prototyping each circuit individually then wrapping it all together. A few mods need to be done to the light sensor to make it breadboard friendly but its doable!
MySensors 2.1.1
Controller - OpenHAB (Virtual Machine)
Gateway - Arduino Mega MQTT Gateway W5100 -
And the prototyping begins! Pretty much all of the breadboard versions of parts have arrived and i will be prototyping each circuit individually then wrapping it all together. A few mods need to be done to the light sensor to make it breadboard friendly but its doable!
@Samuel235 Did you source a breakout version of the OPT3001? It is hard to find.
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@Samuel235 Did you source a breakout version of the OPT3001? It is hard to find.
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@Samuel235 Did you source a breakout version of the OPT3001? It is hard to find.
@Dwalt, this is the one i was looking at but then decided to just solder leads to the sensor itself instead. If i were to get some breakout boards made and maybe solder the sensors on myself, i wonder what the demand would be like, just thinking if its worth doing to help us out.
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@Samuel235
wow, soldering leads on opt3001!
That won't be easy I think, I hope you have very very thin wire and iron! and still not sure...it's a small 2mmx2mm, and delicate, I think you can easily skip this step, it's a simple i2c sensors, no surprise...or maybe you will waste some money if no good tools. I prefer to design evalboards than soldering leads on tiny dfn (doable sometimes but very tricky), it's easier to breadboard and reusable ;)@dwalt
One thing I could do is to release some evalboards I have designed. As it's small, it's cheap at oshpark...I have already made one for opt3001, and have some for others sensors, boosters, buck, buckboost..but I'm little busy actually!
But if I do this you would still have to solder it on pcb, or I should look at the new pcba service... -
@Samuel235
wow, soldering leads on opt3001!
That won't be easy I think, I hope you have very very thin wire and iron! and still not sure...it's a small 2mmx2mm, and delicate, I think you can easily skip this step, it's a simple i2c sensors, no surprise...or maybe you will waste some money if no good tools. I prefer to design evalboards than soldering leads on tiny dfn (doable sometimes but very tricky), it's easier to breadboard and reusable ;)@dwalt
One thing I could do is to release some evalboards I have designed. As it's small, it's cheap at oshpark...I have already made one for opt3001, and have some for others sensors, boosters, buck, buckboost..but I'm little busy actually!
But if I do this you would still have to solder it on pcb, or I should look at the new pcba service...@scalz It seems you have beat me to it with creating a breadboard friendly breakout board for them. If you're confident in the use of this sensor could you double check my schematic and let me know if i have connected it correctly please?
I might get a breakout board for breadboard friendly use designed if you're too busy yourself. Not sure how much call there is for them though.
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@Samuel235 it's few months I did this. like I said I make breakout boards for testing, so I have a small collection now!
This was a breakout with opt3001 and si7021, regulator onboard (with smd jumper to power directly with 3.3v), and few pullups. Same pinout as common chinese sensor boards + interrupt pin for ambiant light:
I will upload at openhardware asap ;) that's lot of things to upload lol! -
0_1462204198812_capturedvideo.MOV
Currently prototyping the optical smoke sensor. I have the buzzer circuit working fine, i also have the circuitry for the optical sensor working. But i can't get it to reflect its IR Light off of smoke and onto the phototransistor.
Waiting on some feedback regarding the Figaro sensor and using with a mosfet from another forum, will post updates when recieved.
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UPDATE!
Figaro TGS5042 Electrochemical Carbon Monoxide Sensor - Working.
Prototype work complete for the carbon monoxide sensor, using the OP AMP style measurement system which includes just 1 Resistor, 1 Capacitor, an OP AMP (Model featured above) and the Sensor itself.
Improvements?
Currently reading through the appnotes given by Figaro for this sensor, heck its a long but interesting read! While it would be great to run with this current setup of 4 components for this circuit, there are things like polarity precautions on the sensor to be taken into consideration. So, with this being said, I'm currently in the process of maybe adding another OP AMP or just a resistor to the keep the sensor shorted out incase the device is isolated from power for any reason. Then there is the accuracy to take into account...
Question
I'm very tempted to amplify the sensors output enough to get to a PPM that is dangerous and then send the alarm off, meaning that at 5v out of the OP AMP it would be enough to send the sensor off and therefor we have a much a higher accuracy between safe and dangerous readings but it would not be able to go over what would be deemed as 'unsafe' levels. OR would you rather me have it so it can read to quite high CO levels despite the 'dangerous' level being around 2/3v out rather than 5v? So, would you rather a high range of readings but lower accuracy or a more accurate but lower range, still enough to detect the dangerous level?
I will be posting images and schematics for the completed parts of the module ASAP for you guys to check out.
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@Samuel235 said:
IONISATION METHOD
I'm very tempted to just use a MQ2 sensor with its circuit on my board rather than a separate board.
MQ2 consumes a lot of energy as every MQ. Also don't rely on your life on this kind of sensors...
Have you tried the bottle of perfume around ?
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@Samuel235 said:
IONISATION METHOD
I'm very tempted to just use a MQ2 sensor with its circuit on my board rather than a separate board.
MQ2 consumes a lot of energy as every MQ. Also don't rely on your life on this kind of sensors...
Have you tried the bottle of perfume around ?
@epierre, you're correct in thinking they are pretty high energy and inaccurate. Would you advise any other sensor at all for this method? I'm currently working on my own custom made optical smoke sensor unit using a IR LED and Phototransistor, but i would like a ionisation method sensor as well.
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@Samuel235 the ionisation for smoke ensor was the old method with radioactive elements.
maybe a particle sensor but you would need to simulate a smoke to set levels, compared to a dusty room I think. Maybe a barbecue test (beware of greasy dusts !)
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I'm encountering some issues regarding my MOSFET enabled PIR sensor. I'm currently using a n-channel MOSFET in a high side switching setup. The issues that i'm getting are that while the gate is pulled low, the sensor is alternating between a HIGH and LOW output, false triggering and when the gate is 5v, high, it is not powering at all.
I'm attempting to get my hands on a p-channel MOSFET to put in a low side switching application to attempt to fix this. I'm assuming that its acting like this because its producing false triggers while the GND is not connected through to ground. I've tried to connect a 10k resistor from drain to gate to eradicate the 'floating' connection, no hope either. If anyone has a link to any p-channel MOSFET that i can get in the UK that would be much appreciated.
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There is currently discussions going on over on the forums at allaboutcircuits.com with myself and a few others regarding this OP AMP and the sensor output readings. I thought i would let you guys know in case you're interested in following the build.
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Once i have the smoke detection worked out and the carbon monoxide circuit more 'suited' i feel we're on the straight and narrow. Adding in things like signing, EEPROM, headers, temp sensors, is all easy and no configuration on the hardware level is needed. So over the next week or two i will be working to get the two sensors correctly working and optimized to the best suited adaptions with this device, then its a case of adding in any functionality that we feel is needed. I would like some feedback from you guys with what features you feel are appropriate for this module, EEPROM, Flash, signal LEDs, security signing, anything at all!
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UPDATE!
The sensor circuitry is now complete to give me a baseline voltage of 0.93V. This will allow for any variation in the sensor and the offset created by the op amp. I have used a double op amp system, the second op amp is performing a voltage follower role to remove any current interference from the voltage divider i have put in place to create the baseline to allow for errors to occur. The below schematic is for this section of the module. Getting close to getting the hardware side complete now. Just a few little things to iron out.
Currently completed hardware:
Carbon Monoxide Sensor
Motion Sensor
Voltage Regulation
Buzzer
Radio
Programming HeadersCurrently working on:
Smoke Sensors (Optical and ionization, i may switch to particle detection though)
Temperature
Humidity
Ambient Light
AC Power connection
DC Power connectionRecommendations - Does anyone have anything else they would to see included onto this module?
Atsha204 signing?
External Flash?
EEPROM?
Status LEDs? -
@Samuel235
good job ;) sorry for not being more active, actually busy :confused:
if you have things which needs security or "anti hacking" like pir for instance, I would add atsha. But it depends of pir usage too.
Eeprom, as you want, but still useful.
Led is always nice when you have enough room. for debug and indicators.
I'm not sure if temp/hum sensor location is best at ceiling...during heating season, I think this is not representative of what we feel...but why not, perhaps in some case it can be useful. So, I prefer to have mine at the middle, not near a door or heater etc...
humm, that make me think I need to hack my smoke sensors too..not done yet :blush: -
@Samuel235
good job ;) sorry for not being more active, actually busy :confused:
if you have things which needs security or "anti hacking" like pir for instance, I would add atsha. But it depends of pir usage too.
Eeprom, as you want, but still useful.
Led is always nice when you have enough room. for debug and indicators.
I'm not sure if temp/hum sensor location is best at ceiling...during heating season, I think this is not representative of what we feel...but why not, perhaps in some case it can be useful. So, I prefer to have mine at the middle, not near a door or heater etc...
humm, that make me think I need to hack my smoke sensors too..not done yet :blush:@scalz, I think i will be adding in what i can with the space, so i'll try and get it all included, EEPROM, ATSHA and if i have any pins left, i will get some debugging LEDs on, not holding my breath though.
As you have experience in using the I2C components i'm using here, could you have a quick look at the following at just let me know that they are okay and will not be conflicting on the I2C lines. I have looked into the addressing and i hope i have done accordingly.
If the Temp reading is completely off the accuracy due to its location i will just use it to compensate for the temp on the Carbon Monoxide sensor.
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Because i'm clueless on the software sides of this, i'd like to ask someone from the @Code-Contributor group to give me their opinion on whether or not i would need some external memory on this module. The code will be including:
- Carbon Monoxide Sensor
- Smoke Sensor
- Optical Sensor
- Ambient light
- Temperature and humidity
- Radio
- PIR Motion Sensor
- ATSHA security IC.
