3.7 PAS Device

These settings tell the Cycle Analyst the physical characteristics of the installed pedal assist device. The CA needs to know the number of pulses per crank revolution and the forward/reverse pedal sense. If there is a torque sensor, it must also know how the torque signal is scaled into meaningful units of Newton-meters. These are one-time settings made at installation time; tuning the way the PAS device operates is achieved by the PAS Configuration Settings in the next section.
[ PASD->Sensr Type ]
Chooser to select the type of PAS sensor installed.
Disabled: There is no PAS device installed. This deactivates all PAS functionality and makes SLim->MxNoPdlSpd inoperative.
Basic PAS: The sensor is a simple cadence sensor, which provides pulses when the cranks are pedaled. Both 1 wire (only pulses with fwd pedaling) and 2 wire (quadrature signals or pulses with separate fwd/dir signal) are supported.
Wheel Trq: The sensor is located in the rear wheel measuring torque on the freehub or freewheel. In this mode there is typically no cadence sensor signal, and the human power is computed by multiplying torque with wheel RPM rather than crank RPM. The rider must maintains more than the ThrshTrq level for power assist to be active.
BB TRQ: The sensor is a custom BB torque device type requiring user configuration of these other settings in this category. In this mode, the human power is calculated from the torque times the pedal cadence:
PASD->PASPoles
PASD->SignlType
PASD->DirPlrty
PASD->TrqScale
PASD->ZeroTorq
Only this torque sensor type allows adjustment of these settings via Setup Utility.
Thun BB:
TDCM BB:
NCTE BB:
Sempu BB:
CyclStokr:
ERider:
ERider_T9:
These are sensors for known device types. These selections cause preconfigured defaults to be copied into place for other settings in this category. The sensor type remains as selected if those other defaults remain unmodified, however, changing a default setting will change this sensor type to 'Custm TRQ'. Downloading one of these preconfigured sensor types from the Setup Utility will similarly set other settings to the associated preconfigured defaults exactly as if the preconfigured type had just been selected by CA Console Setup, overriding the other settings that may have been present in the Setup Utility.
Note: The Sempu BB is manufactured with two different interface styles. The version selectable here has the '2-wire' interface distributed by Grin. Units from other vendors may require subsequently customizing PASD->SignlType to '1-wire' in CA Console Setup.
Similarly, the ERider sensors comes in several varieties as well. The second ERider_T9 option applies to the 2021 model which increased the number of poles from 18 to 36.
[ PASD->PAS Poles ]
Number of pulses generated in one full rotation of the pedal sensor. This is equal to the number of magnets on simple magnetic ring cadence wheels. For internal sensors it can be measured by counting the number of times the P arrow on the SETUP PAS DEVICE preview screen flips up and down during one pedal rotation. This setting is populated automatically when a known sensor type is selected, and must be set correctly for accurate display of human pedal RPM.
[ PASD->Signl Type ]
Both Basic PAS and Torque sensors generate a cadence signal pulse as the cranks are rotated. The signal may pulse only on forward pedal rotation with just a single wire, or it may also indicate direction of rotation which requires two wires.
This setting determines the number of input wires that carry cadence pulses so the CA can best use the available information. The type can be determined by examining the arrows next to the 'PD' on the SETUP PAS DEVICE preview screen as the crank is slowly turned. On a single wire sensor only the P arrow will changes, while on a 2 wire sensor both the P and D arrows will flip UP/DOWN.
1 Wire: Cadence pulses appear on the RPM input with no simultaneous change to the DIR input.
2 Wire: Quadrature encoded cadence pulses appear on both RPM and DIR inputs.
[ PASD->Dir Plrty ]
Controls whether 5V on the Dir pin is considered forward or reverse pedaling. If the Dir pin is not connected, then it should be set to 5V = Fwd. Trial and error tests may be required to find the proper FWD or REV setting if the device is quadrature encoded. If pedal RPM registers only when the cranks are spinning backwards, then simply switch this setting to capture forward rotation instead. This setting is populated automatically when a known sensor type is selected.
[ PASD->Trq Scale ]
Sets the scaling factor for converting torque sensor output voltage to newton meters. For devices that sense torque on only one side of the crank, the value should be doubled to simulate the net left and right pedal torques. The value can be set either positive or negative and is populated automatically when a known sensor type is selected. For TDCM Sensors, additional tuning is required and may be initially guesstimated as the number of teeth on the front chainring. So a 44T chainring would be about 44 Nm/V. This option is present only for torque sensor types.
[ PASD->Trq Fault V ]
Sets the threhold voltage above which the torque sensor signal is defined to be faulty. The CA3 has a weak pull-up to 5V on the torque signal line so that with no sensor attached the signal will sit at 5V, allowing they system to detect disconnected or faulty torque sensors. This value should be set higher than the maximum torque signal the sensor can produce, and then any disconnected wire or failure of the torque sensor will result in a fault condition.
[ PASD->Zero Torq ]
The configured zero-torque offset voltage and the present live torque voltage are displayed. The right button should be pressed with the pedals unloaded (zero torque) which configures a new zero-torque voltage from the present live torque voltage. This voltage is displayed when the button is released. Note that magnetostrictive torque sensors (like THUN and NCTE) don't return to the same zero point very well after high torque excursions. This option is present only for torque sensor types.
3.8 PAS Config

These settings configure how the ebike system responds to pedal action when a PAS device is installed. PAS devices can be adjusted for a wide range of performance and these settings are used to tune the PAS system to your personal taste for both basic pedal cadence sensing as well as more advanced torque sensing devices. The use of an Auxiliary Input device is recommended to increase or decrease the assist level on the fly while riding.
[ PAS->PAS Mode ]*
Chooser to select the pedal assist type. In all cases, assist is enabled only when the throttle is off, and is immediately overridden by throttle control if throttle is applied.
Basic (Pwr), and Torque modes use the Power PID controller to achieve constant power control to the motor. In these modes PLim->WGain may need adjustment to reduce assist oscillation or smooth power application.
No Assist: No assist is provided of any kind. However, because a PAS device is installed, the SLim->MxNoPdlSpd setting has effect even in No Assist mode. This can be useful for simple sensor wheels in locales where regulation imposes a pedaling requirement to enable throttle operation, but where PAS assist is not desired. [Default]
Basic (Pwr): When pedaling is detected with no applied throttle, the motor delivers a constant power assistance equal to the power configured by StrtLevel. This power level can be further modified to increase or decrease with pedal cadence according to the ScaleFctr setting.
Basic (ThO): When pedaling is detected with no applied throttle, ThrOUT is set to 0-100% as configured by StrtLevel, and can be further scaled by ScaleFctr to increase or decrease with pedal RPM.
This mode can be used instead of Basic (Pwr) mode with conventional controllers to have PAS level set the approximate cruising speed of the bike rather than the motor power. It can also be used to have cadence based control of motor torque with torque throttle controllers such as the Phaserunner.
Torque: In this PAS mode, the motor power scales in proportion to the human power as measured by the torque sensor. The StrtLevel term sets baseline power output whenever the cranks are rotating, and the ScaleFctr sets how much each additional watt of human power is then multiplied by the motor.
[ PAS->Strt Level ]*
The meaning of this setting depends on the PAS mode.
Basic (Pwr) Sets the baseline power assist delivered when pedaling without the throttle. If there is a ScaleFctr term to further vary the assist with cadence, then this is the power output up to 50 rpm. It can be nice to set StrtLevel to a comfortable background assist and then use the throttle whenever full power is needed.
Basic (ThO) Sets the baseline ThrOUT percentage delivered when pedaling without the throttle. If there is a ScaleFctr term to vary the the assist with cadence, then this is the throttle percentage up to 50 rpm. For most ebike controllers, this sets an effective percentage of the maximum vehicle speed under pedal assist. For torque throttle controllers, it allows PAS mode to control the motor torque output.
TorqPAS: Sets the baseline power assist delivered when pedaling independant of any measured pedal effort. The target motor power is the this StrtLvl value plus the human power output multipled by the ScaleFctr term. This baseline wattage can also be set to a negative value in order to require a minimal human effort before any motor power is provided.
[ PAS->Scale Factr ]*
The meaning of this setting depends on the PAS mode.
Basic (Pwr): Sets how much the PAS power level varies with pedal cadence above 50rpm. Values between 5-20 W/RPM can provide a boost when downshifting and reduce the need for the rider to use PAS Aux Input adjustments for their desired power. Negative values can be used for single speed bikes to provide more power at low speeds and less as the rider speeds up. A setting of 0 has means that the output power is constant regardless of changes to pedal cadence.
Basic (ThO): Sets how much the throttle output percentage varies with pedal cadence above 50rpm. Recommended for ebikes running a Phaserunner or other torque throttle controller to achieve increased motor torque when downshifting.
TorqPAS: Sets the proportional assistance multiplier that is provided based on your human power pedal input. For instance, a setting of 2.00 W/HW means the electrical motor watts will be double the applied human watts.
[ PAS->Asst Avg ]
Determines the amount of pedal rotation (in terms of the number of pulses) over which the torque signal is averaged. The human pedal torque undulates with each turn of the cranks so the signal must be averaged to prevent corresponding pulses of motor torque. Higher values yield smoother power assist at the cost of slower response to changes in pedal effort.
This should be a multiple PASPoles with sensors like the THUN which only measure torque on one side. It can be set in multiples of half pedal rotations for torque sensors that measure both left and right pedal force (eg TDCM). This setting is populated automatically when a known sensor type is selected.
[ PAS->Strt Thrsh ]
Sets the threshold minimum time between pedal sensing events to cause the CA to assume that the rider is 'pedaling' and activate motor assist. If set to a long period, assist will begin sooner when starting from a standstill, but there will also be a longer delay before the motor cuts out if pedaling stops within a single revolution.
Sensors with more poles give brisker response because the CA gets sensor pulses more quickly, and can use shorter threshold times.
[ PAS->Stop Thrsh ]
After the first complete crank revolution, sets the minimum time that must be maintained between pedal sensing events for the CA to assume that the rider is still pedaling. If the time between pedal events is longer than this threshold, the CA will assume that pedaling has stopped and will cease power assist. Short values result in a more immediate cutout in power, while longer values allow for pedal assist even at slow pedal speeds. Sensible values are usually between ' 0.5x-1.0x the StrtThrsh.
[ PAS->Strt Trq ]
Sets a threshold torque that must be present in order for the Torque PAS mode to power the motor when the vehicle is starting from a standstill with no cadence or speed detected. The threshold should be higher than any casual torque that the rider may produce from resting their foot on the pedals while stopped (Typically 15-20 Nm).
[ PAS->ThrshTrq ]
In PAS->Wheel Trq mode, this sets the threshold torque that must be maintained on the cranks while riding to continue getting motor power. For best performance this value should be just a few Nm above the natural varations and drift in the torque reading.
In both PAS->Wheel Trq and PAS->BB Trq PAS modes, this threshold also serves as a safety to prevent motor power from engaging as a result of improper settings. If the measured torque on the sensor is higher than this threshold voltage either on power-up or on exiting the setup menu, then a Torque Fault will be activated. This fault disables PAS ssistance and is only cleared when the measured torque is less than the pedaling threshold value.
(so many experiments, to do, so little time :lol: 
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