31:[] 2f:{"title":"Processing valve and cycle output","cells":[{"id":0,"value":"md`# Processing valve and cycle output`","pinned":false,"hidden":false,"mode":"ojs"},{"id":66,"value":"md`\nBased on the work done in [here](https://observablehq.com/d/74fdaabb8a248d81), we decided to use two 16-bit registers together to represent _valve on time_ and _number of cycles_.\n\n## Discussion\n\nHere we enter the number of the lower register of the two register set that comprises the reading (the first in the array):`","pinned":false,"hidden":false,"mode":"ojs"},{"id":43,"value":"viewof loInputString = html``","pinned":false,"hidden":false,"mode":"ojs"},{"id":72,"value":"md`\nAnd here we enter the number of the higher register of the two register set that comprises the reading (the second in the array):`","pinned":false,"hidden":false,"mode":"ojs"},{"id":35,"value":"viewof hiInputString = html``","pinned":false,"hidden":false,"mode":"ojs"},{"id":126,"value":"md`\nThose two numbers look like this in binary:\n\n* Low: ${lo} = ${lo_binary_string}\n* High: ${hi} = ${hi_binary_string}\n\nCompositing these two together by putting the higher register in front of the lower register would look like this 32-bit number in binary:\n\n* ${composited_string}\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":159,"value":"md`\nBut we're going to want to divvy up the bits differently, using the left-most 11 bits as ***cycle count*** and the remaining 21 bits as __valve-on time__, like this:\n\n***${composited_string.slice(0,11)}*** __${composited_string.slice(-21)}__\n\nWhile that's a useful visualization of what's going on, the actual composited value (binary or otherwise) is not useful in logic. Here's why.\n\nIf ***cycle count*** goes above 1023, then the very first bit in the composited string will be 1. So, if the ***cycle count*** was 1025 (therefore 10000000001) and **valve-on time** was (unreasonably) 3 (therefore 000000000000000000011), the composited number would be 10000000001000000000000000000011.\n\nBreaking that into the two 16-bit registers we'd get would look like 1000000000100000 0000000000000011, so the numbers we'd be receiving would be ${0b1000000000100000} and ${0b0000000000000011}.\n\nIf we were to convert the composited binary to a composited number, it would look great:\n`","pinned":false,"hidden":false,"mode":"ojs"},{"id":209,"value":"parseInt('10000000001000000000000000000011', 2)","pinned":true,"hidden":false,"mode":"ojs"},{"id":211,"value":"md`But we don't really get binary; we just get numbers, and it's a bunch of costly monkey business to get those binary strings. And it turns out that trying to composite those numbers doesn't give us what we wanted:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":204,"value":"(32800 << 16) + 3","pinned":true,"hidden":false,"mode":"ojs"},{"id":235,"value":"md`And what does that look like in binary?`","pinned":false,"hidden":false,"mode":"ojs"},{"id":238,"value":"((32800 << 16) + 3).toString(2)","pinned":true,"hidden":false,"mode":"ojs"},{"id":240,"value":"md`Holy moley! But it's correct since the first bit is being understood as a sign.\n\nIf I change ***cycle count*** to 513 (therefore 01000000001, making the first bit 0) and go through the whole process again, it works:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":226,"value":"(16416 << 16) + 3","pinned":true,"hidden":false,"mode":"ojs"},{"id":248,"value":"md`Again back to binary:`","pinned":false,"hidden":false,"mode":"ojs"},{"id":251,"value":"((16416 << 16) + 3).toString(2).padStart(32, '0')","pinned":true,"hidden":false,"mode":"ojs"},{"id":257,"value":"md`That all looks as expected.\n\nBut since ***cycle count*** must be able to go above 1023, we obviously can't count on that, so we simply need to ensure that we ***don't use a composited value for anything but binary debugging***.\n\n## The right way\n\n### Cycle Count\n\nThe actual number of times the valve has turned on since the last reset or power cycle.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":186,"value":"hi >>> 5","pinned":true,"hidden":false,"mode":"ojs"},{"id":306,"value":"md`That means _shift the bits all five to the right, letting the rightmost bits disappear, and filling the left side with zeros_.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":188,"value":"md`### Valve-on Time\n\nThe cumulative time that the valve has been on – in [centiseconds](https://en.wiktionary.org/wiki/centisecond) – since the last reset or power cycle.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":193,"value":"((hi & 0b11111) << 16 | lo)","pinned":true,"hidden":false,"mode":"ojs"},{"id":303,"value":"md`That means _get the last five bits of the hi register and move them to the front of the 16-bit lo number_.`","pinned":false,"hidden":false,"mode":"ojs"},{"id":139,"value":"md`## Appendices`","pinned":false,"hidden":false,"mode":"ojs"},{"id":141,"value":"lo = parseInt(loInputString, 10)","pinned":true,"hidden":false,"mode":"ojs"},{"id":145,"value":"hi = parseInt(hiInputString, 10);","pinned":true,"hidden":false,"mode":"ojs"},{"id":151,"value":"lo_binary_string = lo.toString(2).padStart(16, '0')","pinned":true,"hidden":false,"mode":"ojs"},{"id":153,"value":"hi_binary_string = hi.toString(2).padStart(16, '0')","pinned":true,"hidden":false,"mode":"ojs"},{"id":161,"value":"composited_string = hi_binary_string + lo_binary_string","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W31","stdlib":"1","titling":"auto"}