Communication - Revision history

Mariah.files: /* Introduction */

2020-05-28T02:34:32Z

‎Introduction

2019-07-12T19:43:26Z

Added introduction

2019-07-12T18:39:34Z

2019-07-12T18:36:20Z

Adding content from most recent Elcano CAN protocol document

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-| style="border:0.0007in solid #000000;padding-top:0in;padding-bottom:0in;padding-left:0.075in;padding-right:0.075in;"| Drive Speed cm/s
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-| style="background-color:#d0cece;border:0.0007in solid #000000;padding-top:0in;padding-bottom:0in;padding-left:0.075in;padding-right:0.075in;"| Actual Speed cm/s
+| style="background-color:#d0cece;border:0.0007in solid #000000;padding-top:0in;padding-bottom:0in;padding-left:0.075in;padding-right:0.075in;"| Actual Speed mm/s
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← Older revision		Revision as of 19:43, 12 July 2019
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	==Elcano CAN Commands==		==Elcano CAN Commands==
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		+	=== Introduction ===
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		+	Controller Area Network (CAN) is a standard introduced by Bosch in the 1980s. It is widely used to link automotive microprocessors and is required on all cars sold in North America and Europe. Physically there are four wires: Ground, 12V, CanHi and CanLo. A dominant bit has a significant difference between CanHi and CanLo; for a recessive bit the two lines are essentially the same. The interesting parts of a CAN packet are given in the table. The message ID is 11 bits, with low numbers getting priority. A CAN packet contains 0 to 8 bytes of data. The size of a CAN packet is larger, since CAN has significant error detection capability. CAN is a host-less network with most of the work done in hardware.
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-==Revised Elcano CAN Commands==
+==Elcano CAN Commands==
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 gives the relative amount to go, stop or turn. For each, 12 bits will suffice, and fewer bytes than indicated could be used. These are uncalibrated relative amounts from minimum to maximum. At present, positive values are throttle and negative values are brake, and it is impossible to accelerate of brake at the same time. In the future, we may want to allow both simultaneously. At present brakes are either on or off; we may use intermediate values to pulse the brakes. A negative steering value indicates left; positive value indicates right; 0 is straight.
 ===DRIVE (CANID 0x350) ===
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 e.g. &nbsp;commanding 1.5 m/s with a 2.1° left turn gives
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 ===ACTUAL (CANID 0x400) ===
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 Bytes 7,8: Obstacle slant in degrees times 10 (optional). If omitted or 0, the obstacle is perpendicular to the bearing. Otherwise a negative angle indicates that the left side of the obstacle is closer, and a positive angle means the left side is farther than the centroid.
 ===Cone Position (0x480)===