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Week 7 Status Report – Team

Our demo went very well this week. All of the aspects of our player area are functional and ready to go: We have a full deck of RFID cards that can be detected correctly by our RFID reader, we have a prototype chip with embedded resistor and are able to detect the monetary value of a stack of chips, and we have our E-Ink display hooked up so that it displays the cards and chips of the player in real time.

We have also begun production on our shuffler/dealer, as stated in Chris’ weekly update. We will also begin on working on the central computing unit, so that we can link multiple play areas together now that we have one functioning set.  We will continue to work out that before working on incorporating the play area into a more visually pleasing unit.

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Week 7 Status Report – Chris Reed

This week I focused on 3D printing parts for our shuffler and dealer. I made modifications to lower the cost of the parts we wanted to print. I was able to get the first one-sixth dealer tray model printed out as well as the dealing platform to hold the deck of cards. Both pieces came out very sturdy, but since we made them very thin the diagonal slope on the dealing tray is a little flimsy so we may support it with a little tape on the back to ensure it doesn’t snap. For the next dealer tray we print, if we have more money, I may make it a little thicker to try and solve this issue.

We are on schedule for our project right now. Next week, I want to print the shuffling platforms and work with Mark to hook up our motors to both the shuffling and dealing platforms so we can practice dealing and shuffling the cards out. Once we know the mechanics work, we can work on putting them all together into one enclosure as a unit.

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Week 6 Status Report – Chris Reed

This week I started to 3D print the dealer/shuffler enclosure, but ran into some issues. Our model worked fine, but it was much too large to print and would cost too much. Even after making adjustments to the dealer tray model’s design and material thickness, the cost was still very steep for a full model. We are most likely going to pivot to only printing three card trays rather than six, to still show the rotating functionality of our dealer but not have to pay for a full model. Unfortunately, since each tray would take approximately 23 hours to print, we will not have them ready for the demo on Monday, but we do have the models.

This affects our schedule a little bit because it pushes back testing of the dealer and shuffler, but since we need to 3D print less we are saving time on that. We won’t have to adjust much in the schedule, we will just have to 3D print the trays at the same time as assembling the shuffler and dealer motors this coming week.

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Week 6 Status Report – Eric

Work Update

Last week I worked on and am almost finished with the chip detection driver. This was something of a departure from the RFID driver because it was a whole new piece of hardware, and it was built on an I2C driver rather than an SPI driver. Luckily, the INA219 did not require nearly as much setup or configuration as the MFRC522 did.

One hiccup I ran into was that the resistor built into the INA219 was too small to measure the current in the circuit directly. I ended up using another resistor in series with the set of chip resistors in parallel and measuring the potential difference across it, which was large enough to not be a problem for the INA219. Another potential problem is that the accuracy of the INA219 is good, but not perfect. However, I think that by looking at the change in chip value rather than the absolute value at any time we can make some assumptions about what the correct set of values is.

Schedule Update

I believe I’m still on track for my tasks. Next week I will work on the driver for the e-ink screen, which will make the play area subsystem more or less complete software-wise.

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Week 6 Status Report – Mark McKinzie

This week I fabricated a $20 value poker chip as well as building the base contact for the chips. In addition I tested stacking multiple chips and measuring their resistance directly with a multimeter. The chips when stacked sometimes do not fully contact, but with design adjustments, that problem can be eliminated.

The shuffler and dealer complete module cannot all be 3D printed due to cost. The outer card holding base will be constructed from wood, since precision is not a major concern with that part. The dealer and shuffler modules will still be 3D printed, in order for the necessary precision to be achieved, as the motors and gears need to be able to fit in the right places and rotate as necessary.

The schedule is on track and we should have two functioning subsystems by the end of this coming week with adjustments to the chip subsystem that are necessary. We will also construct the exterior for the shuffler and dealer and begin the assembly of the motors, gears, and electronics if time remains.

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Week 6 Status Report – Team

One difficulty the team ran into this week is the prohibitively expensive cost of 3D printing all of the parts for the shuffler and dealer. We will pivot by 3D printing only the dealer and shuffler and constructing our final card holding base out of wood or acrylic, as the precision of that part is less important. This will not change the schedule simply because the 3D prints would have taken close to a day anyway.

For the demo we will have a functioning card detection subsystem and a functioning chip totaling subsystem for individual chips.

 

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Week 5 Status Report – Team

Team Status

No changes were made to the design this week. No changes to the schedule have occured. As we’ve discussed in past team status reports we believe the shuffler/dealer is still the riskiest part of the project, but nothing has changed to make us think we need to starting working more seriously on contingency plans.

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Week 5 Status Report – Eric

Work Update

Last week I completed the RFID driver. As mentioned in the design review and a previous blog post, it was built on top of the Raspberry Pi GPIO library for Python, as well as another library that has some basic SPI primitives. Specifically, it exposes an API that allows the user to create a connection to an SPI device, and transfer data.

I began by writing some relatively simple code to set and read registers on the MFRC522 device, as well as using bitmasks to set or clear specific bits of a register without changing the others. I then began to implement some basic functionality of the MFRC522, as well as a subset of the full RFID spec given by the tags we bought. On the device, we need to initialize it, configure it, and have the ability to send commands to select a tag, send commands to it, and read the response back. In this way we can read the ID of each tag without needing to implement the full set of cryptography operations that are required to read and write to the data sectors of each device.

This work was an iterative process of reading the manufacturer documentation, figuring out which registers and settings were needed, and testing. Progress was slow because while the documentation is detailed, the device has a significant number of features, and there is no guidance on how to perform particular tasks. That made the process largely one of trial and error.

Schedule Update

I believe I’m still on track for my tasks. Next week I will work on the driver for the current shunt so that Mark and I can begin to test the chips he’s been working on.

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Week 5 Status Report – Mark McKinzie

This week I fabricated 2 embedded resistor poker chips. The five and ten dollar valued chips both individually have the correct resistance value. The new purely plastic chips purchased to replace the chips with a metal center plane allowed the embedded resistor model to function properly. Pictures of the cut chips and fully functional chips are below.

This coming week I will fabricate the $20 chip as well as beginning to test stack values with identical chip values, as well as wiring it to the current shunt and raspberry pi and testing it in that manner. In addition I will fabricate the enclosure for the shuffler and dealer, both using 3D printing for the cylindrical portions and likely acrylic for the rectangular portions if 3D printing is expensive.

The schedule remains on track, as the MVP for chips is fabricated and needs only testing.

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Week 5 Status Report – Chris Reed

This week was a particularly busy one for me coming back from Spring Break. I was able to test out our motors that we will be using for the shuffler and dealer, as well as tweak a few final things in our Solidworks model to get the shuffler and dealer encasing ready to 3D print.

Next week, when I have more time to be in the makerspace, I want to 3D print and construct the dealing trays/shuffler top unit so that we will be ready to install the motors and start putting things together. I will also be testing the RFID cards and writing their values now that Eric’s card reading driver is coming along.

The schedule is doing fine, but next week we need to make progress on our dealer prototype so that we have time to make adjustments and calibrate with the deck of cards.