PSIcle sensor: Measure tire pressure with your phone!

Created by Rover Development

Measures your bike's tire pressure with your phone. Spot check pressure before rides, after fixing flats, or fine-tune on the trail.

Latest Updates from Our Project:

End of the road
12 months ago – Sat, Mar 04, 2023 at 02:01:37 PM

It's an update we definitely didn't want to write, but at this point it looks like we won't be able to ship.  We can't get the yield up to the level where it makes sense to create the production tool.  Our last two small test runs have only achieved 60% and 25% yield, respectively.  Sometimes the sensors leak and when we tune the parameters of the molding process so they don't leak, we damage the sensors.  We've also run out of funds, despite doing everything in our power to move slowly and cautiously.  

Of the $39,204 raised, the following was spent:

  • $9,801 on taxes
  • $4,350 on Kickstarter and Backerkit fees
  • $4,470 on Facebook and Google ads for the campaign
  • $14,003 on sensor circuits
  • $8,054 on prototype molds and molding
  • $2,887 on extension tubes and other materials
  • $1,032 on tariffs 

For a total of $44,597 spent, and we still don't have a production mold because we don't have a process that yields well enough to commit to a production mold.  It seems like we're very close, but it has seemed that way for a long time through a number of iterations, so at some point we have to call it.

We thank you for your support and we apologize for the inability to ship.  It seems like there is a viable process in there somewhere, but the funds just aren't sufficient to find it.

Design goal achieved!
about 1 year ago – Thu, Dec 08, 2022 at 02:54:42 PM

We've finally achieved the major milestone of functional prototype sensors that do not leak at 150 psi (~10 bar)!   They were molded at our manufacturer in Taiwan using a prototype mold.  Reaching this point required numerous design changes and a great deal of testing and trials.  There have been a lot of ups and downs for us along the way, and you've been along for the ride.  We appreciate your support!

The next steps will be to produce more test sensors from the prototype mold, and then to commit all of the changes to a production mold that will allow us to produce sensors faster and more inexpensively.  We estimate these two steps will take about two months.  Then if everything goes well, we be making production sensors.  It is likely that we will ship LP sensors first, since they are a bit easier for us to make.  

We may be looking for beta testers for the prototype Low Pressure (<50 psi) sensors.  Our Android app is already on the Google Play store, so it is easy to download and install.  For that reason, we would like beta testers to use Android phones.  Ideally they would also be early bird backers.  Interested backers should email [email protected] and answer the following questions in the body of the email:

  • Do you have an Android phone?
  • What tire pressure do you plan to use with a beta sensor?
  • Are you an early bird backer?

We will notify selected testers when we have some test units ready to ship.  Thank you again!

Functional LP prototype sensors
over 1 year ago – Wed, Nov 02, 2022 at 01:16:07 AM

Hi everyone.  We know it's been a long time, but we've been back and forth between the two suppliers trying to solve the issues.  As the title says, we have a design that should work for LP sensors, but the HP sensors are going to take a bit more work.  We currently don't plan to ship LP sensors until the HP sensors are working as well.  We will let you know if that changes.

In the past several months, we've spoken to both molding vendors, component vendors, and a molding consultant.  We've made several changes to the internal design to improve the issues, and we had to have new parts manufactured and run through the production process.  We have made functional LP sensors that hold up to 60 psi before they start to leak, but the design goal is 150 psi for the HP sensors.  We should be able to achieve that with some more iterations.  The external appearance and specifications should be largely unchanged.

We're being really conscientious about not overspending on the process.  This means we're doing small batches of parts and iterating the design.  We also are modifying and reusing the prototype molds for each new attempt.  Each batch needs to be sent back to us for functional and destructive testing, and this iteration and testing obviously takes a while.  It's possible that we could run out of funds, but the methodical (and slow) iterating and testing is helping to reduce the chances of that.  That's why the updates are trickling out so slowly.

We'd estimate that we have one more round of prototype mold changes, and then some testing and on to the production mold.  This will probably take about three months, but we'll send out an update once the prototype mold is successfully producing HP sensors along with plans to scale up production.

Sensor seal achieved!
over 1 year ago – Sat, Jul 09, 2022 at 05:56:21 PM

Thanks for your patience.  Progress was slow for a long time after the last update but there's a sudden flurry of activity in the past two weeks so it's time for an update.

As you recall, there were two molders we were working with.  Molder A was the original one, and even after two different molds, they couldn't achieve an airtight seal between the mold material and the tube extension, so we started looking for a backup molder.  We found one and they guaranteed they would be able to make the parts seal.  We were cautiously hopeful.

Molder B wanted to see the parts before they would start on the mold.  This got us back into Covid delays.  Molder B is in mainland China, and they had some shutdowns going on.  It took about a month for our shipment to arrive.  Generally it takes only four days.  

It took two weeks to go the last few hundred miles

After Molder B received our parts, they said it would take 60-70 days for the mold to be made.  More delays!  However, they must have either started that lead time before they received the parts, or it was simpler than they anticipated, because we received test parts a couple weeks ago.   We were thrilled to find they have a strong, airtight seal, and they seem very durable.

We're not totally done yet though, because a little bit of rubber is leaking into the sensor element and damaging it.  So the sensor still reads, but the pressure and temperature data is wrong.  This should be much easier to fix than the seal issue was - we just have to tighten the gap a bit between the circuit board and the tube.  The molder is working on testing this now.  We expect to have final prototypes within about two weeks.

After that, we'll have to order the final extensions and start molding and shipping.  Hopefully we don't have more shipping delays, but even if we do, the major product risk seems to be resolved, so after we solve the last minor issue we're on to production!  Thanks for your patience!

Circuit boards complete and threaded extensions
almost 2 years ago – Sat, Apr 16, 2022 at 11:07:23 PM

Hi Everyone.  We've had another month of delays and frustration, but the major milestone since the last update was the completion and receipt of all the circuit boards.  There were numerous delays in both the build and shipping due the entire city of Shenzhen, China being shut down, but we finally received them, and they look and work great.  This is a huge milestone passed on the road to delivery of the units.

We also received some new extensions that we believe may help address the sealing issues.  The new extensions have threads all the way down the body, as shown below.  These threads will provide more surface area for the rubber to adhere to and should improve the sealing.  The last mold trials only had leakage along the smooth body of the original extension, so the zig zag of the threads should help address this.

These extension tubes were also extremely delayed due to the shutdowns in Shenzhen, so we were just able to ship the tubes and circuit boards to the molders this week.  It's a really difficult time to make anything in China with citywide shutdowns affecting numerous different cities.

Due to the delays in receiving the circuit boards and extensions, there have been no new mold trials since last month.  We are working with both molders to define their mold trial schedule for the new molds and will provide an update as soon as we can.  We apologize for all the delays and rest assured, we are just as frustrated as you.  We are pushing forward as hard as we can despite the odds and we are making progress bit by bit.  Thank you for your patience.