#picxie

[awewakemysoul]

a photo of the little beans last year doing what we love most- hiking in nature.

[moarobotics-blog]

We have a 3D printer (and we know how to use it!)

So about a week ago we finally got a 3D printer! We’ve already been busy designing small cases for our breadboard modules, as well as testing the limits of what we can print. We currently have the printer calibrated to within 10 microns to level, and that’s let us do some pretty amazing quality prints!

We’ve been quite busy for the last couple of months helping a company called Aikyn Amusement Co. prototype a variety of electronics they plan to use in a variety of shooting galleries and arcade games. Check them out!

We’re going to be doing a few posts over the next few days going over our printer and the way we calibrated it so precisely.

[moarobotics-blog]

To the Beta and Back!

So we’re back from an exhaustive start to our Beta program. Unfortunately we didn’t have nearly as many beta testers as we could have (6, we wanted at LEAST 10) but it will have to do. At least some people wanted free PICxies :D. Yesterday, our first beta tester, ukscone, received his unit so we can’t wait to see what he does with it. Now that we’re in cruise mode with the beta we can turn our focus to the PICxie Kickstarter. Once we get some feed back from the beta testers, we will proceed forward with that. The beta gave us a good dry run of our internal shipping process, and verified our expectations regarding the  costs associated with shipping lightweight packages internationally. We’ll have more news on all of that soon.

[moarobotics-blog]

SPI Insanity

Well we’ve had a very busy week! We’ve received the components ahead of schedule. Cases are on schedule, and the PCBs we’re pretty sure are on schedule. Our design created some questions from the Elecrow engineers we had to address prior to them being sent to production.

We’ve been bashing our head against trying to create a good example for using SPI to communicate with the MicroSD card. We were initially simply resetting the card and checking the response, however upon trying to send more commands we would get all sorts of nonsense, everything from illegal response values to the card hanging up and today...we finally discovered the issue...

Usually when using an SPI interface, the master has exclusive control of the clock, the slave can only send data back to the master while the master is sending data to the slave and toggling the clock input. We had initially assumed that the XC8 library functions would operate similarily we were wrong!

With the XC8 SPI libraries, calling ReadSPI will generate clock cycles

Just check this snippet of code straight from the library...

unsigned char ReadSPI2( void ) {      unsigned char TempVar;      TempVar = SSP2BUF;       //Clear BF      PIR2bits.SSP2IF = 0;     //Clear interrupt flag      SSP2BUF = 0x00;          // initiate bus cycle      //while ( !SSP2STATbits.BF );                // wait until cycle complete      while(!PIR2bits.SSP2IF); //wait until cycle complete     return ( SSP2BUF );      // return with byte read }

...as you can clearly see it DOES in fact generate clock cycles on its own by writing a dummy byte out of the SPI channel. However this isn’t documented anywhere that we’ve been able to find, and is clearly something that would assail someone trying to use our devkit. With how we’ve learned to use SPI we would write something like:

Wrong Way: WriteSPI2(0xFF); res = ReadSPI2();

But with these libraries, that would actually write out 0xFF AND 0x00 before we read our result, potentially causing us to miss our response as we were expecting to receive it on the first write. The correct way, with MPLabX and XC8 is this

Right Way: res=ReadSPI2();

Hopefully this will save some other people time.

[moarobotics-blog]

Cheaper PICxies? It’s possible!

So we finally managed to fill our open positions for the PICxie beta! Now we can finally focus on the actual beta rather than recruiting for it. We’ve ordered all of the parts and just as we calculated there was a 20% reduction in production costs. This recent data shows that we might be able to sell these for $44.99! Possibly even $39.99!! Something we are striving to achieve for you guys, we want PICxie to be a very accessible platform. We need 2 things to make that happen:

Demand/Volume

We need enough people to buy PICxies to reduce the costs of components, cables, and LiPo batteries. The batteries in particular cost us ~$2.00, but if we had a demand of 50-100 units we could order in bulk and get these for 1/4 the price. At that demand the cost for components drops by about 50% as well.

Equipment

We really need a 3D printer in-house. We’ve already settled on the Form1+ (Possibly Form2) because it will have no issue printing the cube case that PICxie uses. The problem is we cannot afford to buy one based on our budget. Currently we spend ~$10 on each case, however with a 3D printer this would drop to 1/10th of the cost.

We can solve both of these issues rather elegantly with crowdfunding. Additionally this would generate PR which is ALWAYS good. We will be doing another Kickstarter, we like Kickstarter because it’s low risk to you guys financially, and well respected as a platform. We know exactly how much we need to raise in order to A) Fulfill rewards and B) Get the equipment we need to drive the cost even lower! We’ll post more about our Kickstarter after the beta units have been sent out.

[moarobotics-blog]

PICxie vs Raspi SenseHAT

So a beta user made the comparison between PICxie and the Raspberry PI SenseHAT. And we wanted to formally compare the two platforms:

As you can see the platforms are pretty comparable, what is better actually depends on what you need exactly. If you need a stand-alone, compact sensing platform that requires NO additional hardware, go with a PICxie! However if you have a Raspberry PI lying around the SenseHAT is a cheaper option for the same functionality. Both platforms have a lot of merits and we’d recommend choosing one suitable for you.

[moarobotics-blog]

Open Beta Access for Sale

So we had quite a few people who did not respond to their beta e-mails, we contacted a lot of the other signups and a lot of people are not responding. If you signed up please check your spam folder. Since only 5/13 of our nominees actually completed the signup process, we have 8 spots open in our Beta program, if you would like early access to the PICxie 8-bit development kit, please check our store page at: http://www.moarobotics.com/products/devkits/ 

We’re no longer offering the free PICxie. Only people who have signed up in the Open Beta run will be receiving a free PICxie, others will have to pay $4.99 to access the program.

Open Source Initiative

Also on the product page are the source AND production files for PICxie, if you are interested in rolling your own PICxie unit, you can download all the files necessary on the product page! FREE! 100% Free. And please if you do so, please credit us and let us know! We’d love to hear about any changes you make to our platform or improvements you come up with. We also love to hear about any neat projects you use PICxie in, so please let us know! :D 

[moarrobotics-blog]

Open Beta Spots

So we had quite a few people who did not respond to their beta e-mails. If you signed up please check your spam folder. Since only 4/13 of our nominees actually completed the signup process, we have 9 spots open in our Beta program, if you would like early access to the PICxie 8-bit development kit, please check our store page at: http://www.moarobotics.com/products/devkits/