Looking for volunteers to create a project

Hello everyone,
my topic will seem a little strange, but here is the situation.

We are a community of 4000 members of whitewater sports and we want to have a tool for measuring the level of some rivers. Our knowledge in electronics is quite weak and would like to have your help to complete this project. We are looking for accurate and detailed answers from members who are familiar with the product. I have in the past created a similar project with the “Hologram dash” but I spent a crazy time completing it, which I would like to avoid this time. However it worked well, but would like to evolve towards the Particle product. The whole project will be very simple:
-Battery operated in remote location.
-The use of 3G and later Cat-M1 when available in Canada.
-An economical ultrasonic sensor (JSN-SR04T-rev2) and a 5v pressure transducer. (want to try both options).
-2 buttons for calibrating the measurement if necessary.
-1 measurement every hour
-Webhook to Thingspeak and possibly to website
-Watchdog Adafruit TPL5110 Low Power Breakout Timer
-Low cost and Simple design for noobies in order to make the project open source after field tests.

We are looking for help from a few members to participate in the development of the project, otherwise the project may not take place, which would be sad for the community.

thank you for your support and understanding.

I’m currently working on a tracker for surfskiing (different type of whitewater :sunglasses:) based on the boron with gps, IMU, and small OLED. I’m interested to work on a wave height monitoring device next, which is very similar to what you’re looking for. I have experience with an MS5837-02 pressure sensor which worked very well for the water level of a tank (others have used it to measure water level in ocean caves). What type of help are you looking for specifically?

I’m about to start working on a similar project.
My plan is a Boron LTE with a TPL5111, tiny solar panel, and upload hourly data to ThingSpeak.
But I’m leaning towards a MaxBotix MB7051 XL instead of a JSN-SR04.
The MB7051 has a 35’ measurement range, for installing on the side of a bridge to measure water level.

I’d be happy to share my results with you.

I looking for a full help, by starting by selecting the component needed and developping most of the code. Do you have more information about “MS5837-02” I’m curious how you put it in the water as it doesn’t seems to have stainless diaphragm over it. I was looking for a 15$ 5psi pressure transducer with compensated temperature found on ebay. I’m measuring bout 2-3 meters of water. My project is clearly simplier than yours

Yes I’ll be happy to follow your works. I don’t need that long range so I’ll stick to a cheaper sensor.
I expect working on the Boron 3G for couple of years. But I’m worried about the lack of deep sleep as other says (but documentation indicate there are sleeps modes). But with TPL511(1,0) I expect breaking the entire power supply to the board if it can push 2A for connection peak. Isn’t shutting down the board repeatedly may occur problem? You see, I have a lot to learn and this is not in my usual field of activity!

Do you have project files / specs? You built something using a Dash… More detailed descriptions of what you’re looking for, e.g. water depth, mounting expectations, number of units, power expectations (solar?), diagram, project write-up, etc.

Re: MS5837 see https://www.te.com/usa-en/product-CAT-BLPS0059.html, there are also versions for other pressure ranges available. As a project, see https://thecavepearlproject.org/2014/03/27/adding-a-ms5803-02-high-resolution-pressure-sensor/ (I forget why I ended up with the MS5837 vs. MS5803, I believe because of the better mounting option thanks to the o-ring groove). The way I use it is: a long PVC pipe, the sensor mounted in a cap at the bottom, the microcontroller mounted in a housing at the top, then simply mount the PVC pipe against the sidewall of the tank so the sensor is at the bottom and the microcontoller sticks out. My version uses a simple RF69 radio since it’s around my house.

I wouldn’t worry about the current lack of sleep modes on the Boron, the code to implement them is already in github, so it shouldn’t take too long. In any case, “there are ways around this” :smile:

NB: tu parles Français?

While there may or may not be a deep sleep as we know it from Gen1&2 the considerably lower power demands of these devices will not make you miss it greatly.
The nRF52840 has multiple sleep modes to offer and especially the LTE Cat M1 will also consume a lot less than the alternative radios but before decissions about which sleep/low power modes will actually be available for user code are made hard numbers are sparse.

I don’t have sketches right now. I wired the Dash without any pcb and this it outside my capability. I’m not sure if I should expose the whole project here but here few more things: water depth, about from 0 to 3meters. We plan to mount theses devides under bridges with a clamp style or glued for concrete bridge. The one I made was working 2 months per 2000ma lipo, hourly measurements with ultrasonic. I expect the same with boron 3G. With couple of battery, I can expect run the entire year so solar power is not a priority for now. I didn’t add a watchdog and never had problem, but I suppose it could happen.
*oui je parle francais

about boron 3G, I don’t seems to find any info about current consumption. Look at my previous reply, I’m attempting pretty long autonomy with lipo.

There is no current consumption info on the boron yet. The design isn’t well optimized for low power, unfortunately. I expect to see 50uA-100uA sleep at best. In theory it should be able to just run for a year on one 2600mAh 18650 LiPo, in theory…

Why not?

NB, if you’re wondering who this ‘tve’ guys is, you can see some of my recent projects at https://blog.voneicken.com/projects/ and it’s easy to google my name…

I wasn’t sure if this topic would be the one for the project creation or just finding some volunteer / see if I could get some help.

As mentioned, the Boron 3G will use more battery power than the LTE version.
However, since you’ve already mentioned using an external timer, this wont impact you as much.

The Self Discharge for Li-On Cells is going to hurt you for a 1-year deployment without recharge.
That can be easily overcome with a tiny Solar Panel, or switch to Primary Batteries.

Here’s a trial I performed with both examples (Li-Po +Solar & Primaries Only) using a TPL5111 and Boron LTE.

Summary of Results:

  1. The 0.5 watt Solar Panel maintained the Li-Po ~90% Charge with a 5 minute Cycle interval (Startup, Cellular Connection & Publish). SoC ranges from 93% (daytime) to 85% (early morning before sunrise)

  2. The 3xAA performed 10,000 Cycles before depleting the batteries (equals ~1 year @ 1 hour Cycle interval).

The downside to using the Enable Pin is the Boron performs a full handshake for each cycle.
(Hourly cycle interval might cost you $1 per month over the minimum Cellular Bill.)

The benefit is you don’t need to wait for Sleep Modes, or depend on them.

Since your project is outdoors, I would add a tiny Solar Panel.

Keep in mind a ultrasonic sensor will need to have a measurement range much larger than your expected water level range. It gets mounted to a bridge that’s a good bit higher than the max water level expected. IE, your 3 meter range of water may require a 10 meter sensor depending on it’s mounting location. That’s the reason I’m going with the 35’ range MaxBotix sensor I mentioned.

I did two very quick back-of-the-envelope calculations:

  1. Hourly wake-up for 5 seconds, sleep @100uA, wake at 150mA avg: 1 year run-time on 2600mAh, wake periods account for 68% of total power consumption
  2. Hourly wake-up for 10 seconds, sleep @200uA, wake at 300mA avg: 0.3 year run-time on 2600mAh, wake periods account for 81% of total power consumption

I believe #1 is achievable using the LTE modem, I fear #2 is more typical of the 3G modem. Given that the wake periods consume most of the power I don’t see that an external timer which cuts sleep power to virtually zero helps all that much. I used 2600mAh 'cause that’s the capacity of the 18650’s I tend to use, all this is just to get a feeling for the space.

WRT self-discharge, I’m not convinced that it’s an issue. See http://www.candlepowerforums.com/vb/showthread.php?115206-Li-Ion-Self-Discharge-Rate-Test

Don’t always believe what you see on the internet :slight_smile:
The last 3 months of his readings the voltage didn’t change. I guess the battery decided to stop self discharging there, LOL.

@mikemoy Did you perhaps forget to attach a link to some data to your remark?

For example: https://ripitapart.com/2018/05/01/completed-self-discharge-test-of-kentli-ph5-1-5v-li-ion-aa-part-6/ (took 3 years to test the self-discharge of this Li-Ion cell!)

nope :wink:
If you want real / accurate data you always go to the manufacturer of the battery your using. Never some guy you never heard of who posts something. You don’t know if its a guy who is a total novice who could not tell a resistor apart from a cap. If he is using a $9.00 meter, or if he has been calibrating his equipment yearly. Did he use the same meter for every test point in the chart for the whole 3 years? Same meter leads, just to many variables to assume. I am not saying your wrong, just saying be careful what you get off the net.

I am not saying your wrong, just saying be careful what you get off the net.

Oh really?

If you want real / accurate data you always go to the manufacturer of the battery your using.

Can you please point me to such data for some 18650 cell?

By just asking that question shows you never registered your company to any of the top tier manufactures web sites, then contacted support to get the full data sheet (not the short form they list for the general public).

I’m not here to argue with you.

regarding self discharge, I’m positive with the rate it will drop. So many cordless tools use theses cells and it will last the year. If this come to be a problem, I could add a solar panel, but for the moment, I will keep it simple for testing.

Rftop is a pretty knowledgeable person imo and he is giving me some help with the original request. I don’t have all the hardware yet and I’m wishing to know what to buy apart from boron, ultrasonic sensor, 0.5-4.5v pressure transducer, tpl5111. I may need a step up voltage booster (maybe this one: on-off step up booster).
is something missing/would be good to have on hand for further developpement?

Tve, I read your page about pressure sensor and I’m a bit afraid to go this way (with this particular hardware). I’m goind to test 05-4.5 stainless pressure transducer) and it claim to be presice enough with temperature change. Tested in the past the same unit and was about 30%off reading with 20celsius change, so I’m ready to ask a full refund again and look toward ultrasonic sensor only. I’m not ready to make a claibrating chart myself to make it reliable.