Well, as I posted in my other post, more failures than successes. I get 60/sec out of the 74hc74. I need to make sure the unused pins are high in the data sheet. I have them high right now (testes with voltmeter).

Did you know that you have to supply 5v to the encoder?

Well, i did but didnt.

The 4013 reports around 19300 pulses per second The 74hc74 reports around 19500 pulses per second

I find this interesting because I would have thought that they would have been the same.

Without the flip flop inline I get 38860/s. This could be pushing the digital read limit of the arduino I suppose. The motor is rated to run at 42291/s but my battery may not be fully charged and the simple serial mode that I am running in may not be going truly 100% on the motor.

I tested the battery with a volt meter and got 13.36v, so that should be good. I tested the output from the sabertooth that I am using for testing and got 10.94v to the motor so it should be running a bit slower than 40 RPM (about .911% which this tick count amount is close to at .918% of max speed). I will have to look into the sabertooth that I have to see if something is weird or if this is expected...

so, which is more accurate? hmm 4013 - 193002 = 38600 or 260 less than what the counts reports without the flip flop in place. 74hc74 - 195002 = 39000 or 140 more than the count reports without the flip flop in place.

It is impossible to test accurately to say because the ticks per second does not stay consistent, but I think the 74hc74 wins. I wonder if we are pushing the limit of the 4013 that I have with this encoder. The 74hc74 has 10 times the processing speed of the 4013.

PCB's ordered for the first batch of 74hc74 based Flip Flops. I managed to get the first order down to a quantity of 64. This did hike up the price some per unit, but it will be good for the first test of the PCB design without spending too much money.

I was also doing some searching online for Quad encoder android issues and it seems that there were some articles about people getting too high of counts and needing to use a circuit like this to handle the issues they saw. Who knows, I am sure that I will sell a few here if anyone needs them. If not, no problem, they will be used by the few people that I know who need them (including me). These are going to be sold by me and not CochranRobotics. I will sell CochranRobotics what it needs for Rafiki.

Now that this is complete and I have 4 working prototypes, I will start coding again and wont be on as much. Thanks again to everyone for their help!

Please post when/if you start selling these. I would like a couple myself.

A large majority of the initial order will be up for sale. I am working on the sub-controller circuit board for Rafiki and decided to include these on the sub-controller board. I will build a couple of them to test the design to make sure it all works as expected and then put the rest up for sale.

I should have 12 of these up for sale in a couple of weeks. This will help to offset the cost associated with having boards manufactured. It costs me about $3.36 per unit for parts. Time is the only variable that I don't know yet along with shipping and such. I don't think it will take long to put the parts on the board at all, but you never know until you do a few of these. I will figure up a price that I think is fair after I make the first couple based on the time it takes to assemble them. All of the parts have been ordered and I am now just waiting to receive them.

I just want to set expectations up front if anyone is considering purchasing.

These will be "made in someone's garage", so please expect a working product but if you order 2 of them, I can't promise that these two will be in the exact same form factor. One might be a bit more narrow than another for example. These are being put on an additional order which is the primary focus of the order. I spaced these in a way that I should have no issue scoring the board and breaking each one off, but I didn't pay extra for the boards to be scored. I will probably cut these out with a wet saw. These are prototype boards. They will be about 1 inch by about 1.75 inches in size.

I will solder the 7474 chip, resistors and cap to the board and then alcohol wash the flux off the board before shipping. I will leave the header rows blank so that you can put whatever you want for headers. There is an input and output header row (5 pins each) labeled Roo (output) and Enc for the encoder side (input). All of the pins are labeled (G I A VCC B). I (index) is now connected through the circuit if you need it. You will have to solder in a 2k7 resistor to use Index and enable it to go through the circuit. There is no divide by to happening on Index. There is no branding information on these to keep them as small as possible. Right now I think the cost of an assembled board would be about $10. If you just want the parts and want to build it yourself, I think I will charge about $6.00. I will make a run to the post office weekly to ship out orders.

I updated the information above. There was an issue in making these boards, so I decided to make some changes that I wanted to make anyway. The Index signal is now passed through a pullup resistor slot. If you want to use it, you would just solder a 2k7 resistor in and Index will be passed through the circuit. I also will only have 12 of these for sale. Unfortunately, this issue will push the making of these boards back about a week or so.

I decided to make some of the parts instead of buying them. The main part that I will be making besides the main sub-controller board for Rafiki is a USB type A breakout board. This board costs about $4.00 shipped online and I will need quite a few of them and can make them for about $1.40. Because of this I am making 15 of these, 3 USB signal splitters, 3 74hc74 based logic divide by 2 circuits and 1 2x 74hc74 based logic divide by 2 circuit per board that is manufactured. This will give me 12 74HC74 flip flop circuits and 4 2x flip flop circuits that I will be able to sell. It also gives me 50 usb breakouts and 4 usb signal splitters that I will be able to sell per circuit board order. I will put these up for sale and see what happens. The USB type A breakouts can be ordered online from other companies for what I would sell them for, but if you are buying any of the other two parts, this would be beneficial to include to save on shipping I guess. If you were to buy the USB Type A divider circuit then you might need 3 of these USB Type A Break out boards to go with it for example. I would sell the other 3 Rafiki boards but they are not general enough of a product to sell.

Anyway, waiting for the parts and then I will build some and open a store on my website.

@David, I haven't read the whole post I take it this is for slam if so I'm in for two of them that your building